Thermoplastic polyurethane compositions for golf balls

ABSTRACT

A golf ball comprising:
         (A) a core;   (B) optionally, at least one intermediate layer; and   (C) a cover layer,   wherein the cover layer or the intermediate layer comprises a polyurethane-urea composition that is the reaction product of:   (i) a thermoplastic polyurethane-urea formed as a reaction product of (a) a diol or polyol, (b) a first isocyanate, and (c) an amine chain extender; and   (ii) a crosslinking agent.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.62/190,652, filed Jul. 9, 2015, which is incorporated herein byreference.

BACKGROUND

Conventionally, golf ball cover and intermediate layers are positionedover a core or other internal layer using one of three methods: casting,injection molding, or compression molding. Of the three methods,injection molding is most preferred, due to the efficiencies gained byits use. Injection molding generally involves using a mold having one ormore sets of two hemispherical mold sections that mate to form aspherical cavity during the molding process. The pairs of mold sectionsare configured to define a spherical cavity in their interior whenmated. When used to mold an outer cover layer for a golf ball, the moldsections can be configured so that the inner surfaces that mate to formthe spherical cavity include protrusions configured to form dimples onthe outer surface of the molded cover layer. The mold sections areconnected to openings, or gates, evenly distributed near or around theparting line, or point of intersection, of the mold sections throughwhich the material to be molded flows into the cavity. The gates areconnected to a runner and a sprue that serve to channel the moldingmaterial through the gates. When used to mold a layer onto an existingstructure, such as a ball core, the mold includes a number of supportpins disposed throughout the mold sections. The support pins areconfigured to be retractable, moving into and out of the cavityperpendicular to the spherical cavity surface. The support pins maintainthe position of the core while the molten material flows through thegates into the cavity between the core and the mold sections. The molditself may be a cold mold or a heated mold. In the case of a heatedmold, thermal energy is applied to the material in the mold so that achemical reaction may take place in the material. Because thermosetmaterials have desirable mechanical properties, it would be beneficialto producers of golf balls using this process. Unfortunately, thermosetmaterials generally are not well suited for injection molding, becauseas the reactants for thermoset polyurethane are mixed, they begin tocure and become highly viscous while traveling through the sprue andinto the runners of the injection mold, leading to injectiondifficulties. For this reason, thermoset materials typically are formedinto a ball layer using a casting process free of any injection moldingsteps.

In contrast to injection molding, which generally is used to preparelayers from thermoplastic materials, casting often is used to preparelayers from thermoset material (i.e., materials that cure irreversibly).In a casting process, the thermoset material is added directly to themold sections immediately after it is created. Then, the material isallowed to partially cure to a gelatinous state, so that it will supportthe weight of a core. Once cured to this state, the core is positionedin one of the mold sections, and the two mold sections are then mated.The material then cures to completion, forming a layer around the core.The timing of the positioning of the core is crucial for forming a layerhaving uniform thickness. The equipment used for this positioning arecostly, because the core must be centered in the material in itsgelatinous state, and at least one of the mold sections, after havingmaterial positioned therein, must be turned over and positioned onto itscorresponding mold section. Casting processes often lead to air pocketsand voids in the layer being formed, resulting in a high incidence ofrejected golf balls. The cost of rejected balls, complex equipment, andthe exacting nature of the process combine to make casting a costlyprocess in relation to injection molding.

Compression molding of a ball layer typically requires the initial stepof making half shells by injection molding the layer material into acold injection mold. The half shells then are positioned in acompression mold around a ball core, whereupon heat and pressure areused to mold the half shells into a complete layer over the core.Compression molding also can be used as a curing step after injectionmolding. In such a process, an outer layer of thermally curable materialis injection molded around a core in a cold mold. After the materialsolidifies, the ball is removed and placed into a mold, in which heatand pressure are applied to the ball to induce curing in the outerlayer.

One material used in ball layers is polyurethane. Polyurethane typicallyis formed as the reaction product of a diol or polyol, along with anisocyanate. The reaction also can incorporate a chain extenderconfigured to harden the polyurethane formed by the reaction.Thermoplastic polyurethanes have generally linear molecular structuresand incorporate physical crosslinking that can be reversibly broken atelevated temperatures. As a result, thermoplastic polyurethanes can bemade to flow readily, as is required for injection molding processes. Incontrast, thermoset polyurethanes have generally networked structurethat incorporate irreversible chemical crosslinking. As a result,thermoset polyurethanes do not flow freely, even when heated.

Thermoplastic and thermoset polyurethanes both have been used in golfball layers, and each provides for certain advantages. Because of theirexcellent flowability, thermoplastic polyurethanes can be positionedreadily around a golf ball core using injection molding. Unfortunately,golf ball covers comprising thermoplastic polyurethane exhibit poorshear-cut resistance. Thus, while thermoplastic polyurethane covers areless expensive to make due to their superior processability, they arenot favored due to the resulting inferior ball performance. In contrast,thermoset polyurethane exhibits high shear-cut resistance and is muchmore scuff- and cut-resistant than thermoplastic polyurethane. However,the irreversible crosslinks in the thermoset polyurethane structure makeit unsuitable for use in injection molding processes conventionally usedfor thermoplastic materials.

Polyurethanes exhibit good mechanical properties, and those propertiescan be modified with variations of material compositions, such as typesand ratios of polyol, diisocyanate, and curatives. The golf ballindustry has been using polyurethane for making a golf ball cover layereither by casting, RIM, or injection molding. In particular, casting andRIM are the methods for cast urethane to make golf ball covers.Injection molding is the method used to make golf ball cover layersusing thermoplastic polyurethane. However, thermoplastic polyurethanesnever showed acceptable shear cut resistance compared to cast urethanes.

SUMMARY

Disclosed herein is a golf ball comprising:

(A) a core;

(B) optionally, at least one intermediate layer; and

(C) a cover layer,

wherein the cover layer or the intermediate layer comprises apolyurethane-urea composition that is the reaction product of:

(i) a thermoplastic polyurethane-urea formed as a reaction product of(a) a diol or polyol, (b) a first isocyanate, and (c) an amine chainextender; and

(ii) a crosslinking agent.

Also disclosed herein is a golf ball comprising:

(A) a core;

(B) optionally, at least one intermediate layer; and

(C) a cover layer,

wherein the cover layer or the intermediate layer comprises apolyurethane-urea composition that is formed from:

(i) a crosslinked polyurethane-urea that is a reaction product of (a) adiol or polyol, (b) a first isocyanate, and (c) an amine chain extender.

Further disclosed herein is a method for making a golf ball comprising:

forming a layer over a golf ball core or forming a layer over a golfball intermediate layer, wherein the layer comprises a crosslinkablethermoplastic polyurethane-urea that is a reaction product of (a) a diolor polyol, (b) a first isocyanate, and (c) an amine chain extender; and

crosslinking the crosslinkable thermoplastic polyurethane-urea.

Also disclosed herein is a method for making a golf ball comprising:

forming a layer over a golf ball core or forming a layer over a golfball intermediate layer, wherein the layer comprises a UV-crosslinkablethermoplastic polyurethane, UV-crosslinkable thermoplastic polyurea, ora UV-crosslinkable thermoplastic polyurethane-urea; and

irradiating the layer with UV light under conditions sufficient forcrosslinking the UV-crosslinkable thermoplastic polyurethane,UV-crosslinkable thermoplastic polyurea, or a UV-crosslinkablethermoplastic polyurethane-urea.

The foregoing will become more apparent from the following detaileddescription, which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a three-piece golf ball 1 comprising a solid centeror core 2, an intermediate layer 3, and an outer cover layer 4.

FIG. 2 illustrates a four-piece golf ball 1 comprising a core 2, and anouter cover layer 5, an inner intermediate layer 3, and an outerintermediate layer 4.

Although FIGS. 1 and 2 illustrate only three- and four-piece golf ballconstructions, golf balls of the present invention may comprise from 1to at least 5 intermediate layer(s), preferably from 1 to 3 intermediatelayer(s), more preferably from 1 to 2 intermediate layer(s).

DETAILED DESCRIPTION

Any numerical values recited herein include all values from the lowervalue to the upper value in increments of one unit provided that thereis a separation of at least 2 units between any lower value and anyhigher value. As an example, if it is stated that the amount of acomponent or a value of a process variable is from 1 to 90, preferablyfrom 20 to 80, more preferably from 30 to 70, it is intended that valuessuch as 15 to 85, 22 to 68, 43 to 51, 30 to 32 etc. are expresslyenumerated in this specification. For values, which have less than oneunit difference, one unit is considered to be 0.1, 0.01, 0.001, or0.0001 as appropriate. Thus all possible combinations of numericalvalues between the lowest value and the highest value enumerated hereinare said to be expressly stated in this application.

The term “bimodal polymer” refers to a polymer comprising two mainfractions and more specifically to the form of the polymers molecularweight distribution curve, i.e., the appearance of the graph of thepolymer weight fraction as function of its molecular weight. When themolecular weight distribution curves from these fractions aresuperimposed into the molecular weight distribution curve for the totalresulting polymer product, that curve will show two maxima or at leastbe distinctly broadened in comparison with the curves for the individualfractions. Such a polymer product is called bimodal. It is to be notedhere that also the chemical compositions of the two fractions may bedifferent.

As used herein, the term “block copolymer” is intended to mean a polymercomprising two or more homopolymer subunits linked by covalent bonds.The union of the homopolymer subunits may require an intermediatenon-repeating subunit, known as a junction block. Block copolymers withtwo or three distinct blocks are called diblock copolymers and triblockcopolymers, respectively.

The term “core” is intended to mean the elastic center of a golf ball.The core may be a unitary core having a center it may have one or more“core layers” of elastic material, which are usually made of rubberymaterial such as diene rubbers.

The term “cover layer” is intended to mean the outermost layer of thegolf ball; this is the layer that is directly in contact with paintand/or ink on the surface of the golf ball. If the cover consists of twoor more layers, only the outermost layer is designated the cover layer,and the remaining layers (excluding the outermost layer) are commonlydesignated intermediate layers as herein defined. The term “outer coverlayer” as used herein is used interchangeably with the term “coverlayer.”

The term “fiber” as used herein is a general term for which thedefinition given in Engineered Materials Handbook, Vol. 2, “EngineeringPlastics”, published by A.S.M. International, Metals Park, Ohio, USA, isrelied upon to refer to filamentary materials with a finite length thatis at least 100 times its diameter, which is typically 0.10 to 0.13 mm(0.004 to 0.005 in.). Fibers can be continuous or specific short lengths(discontinuous), normally no less than 3.2 mm (⅛ in.). Although fibersaccording to this definition are preferred, fiber segments, i.e., partsof fibers having lengths less than the aforementioned are alsoconsidered to be encompassed by the invention. Thus, the terms “fibers”and “fiber segments” are used herein. In the claims appearing at the endof this disclosure in particular, the expression “fibers or fibersegments” and “fiber elements” are used to encompass both fibers andfiber segments.

The term “hydrocarbyl” is intended to mean any aliphatic,cycloaliphatic, aromatic, aryl substituted aliphatic, aryl substitutedcycloaliphatic, aliphatic substituted aromatic, or cycloaliphaticsubstituted aromatic groups. The aliphatic or cycloaliphatic groups arepreferably saturated. Likewise, the term “hydrocarbyloxy” means ahydrocarbyl group having an oxygen linkage between it and the carbonatom to which it is attached.

The term “carboxy group” is intended to mean any group containing acarbon atom that is linked by a double bond to one oxygen atom and byone single bond to another carbon atom and by another single bond to anoxygen, nitrogen, sulfur, or another carboxy carbon. One suitablecarboxy group contained in the carboxylated elastomers used in thepresent invention may be represented by the general formula —COOR,wherein R may be a hydrogen, a metal (for example, an alkali metal, analkaline earth metal, or a transition metal), an ammonium or aquaternary ammonium group, an acyl group (for example acetyl (CH₃C(O))group), an alkyl group (such as an ester), an acid anhydride group, andcombinations thereof. Examples of suitable carboxy groups include, butare not limited to, carboxylic acid, carboxy esters, carboxy acidanhydrides, and monovalent, divalent and trivalent metal salts ofcarboxy acids, derivatives thereof and any and combinations thereof.

The term “mantle layer” may be used interchangeably herein with theterms “intermediate layer” and is intended to mean any layer(s) in agolf ball disposed between the core and the outer cover layer. Should aball have more than one mantle layer, these may be distinguished as“inner intermediate layer” or “inner mantle layer” which terms may beused interchangeably to refer to the intermediate layer nearest the coreand furthest from the outer cover, as opposed to the “outer intermediatelayer” or “outer mantle layer” which terms may also used interchangeablyto refer to the intermediate layer furthest from the core and closest tothe outer cover, and if there are three intermediate layers, these maybe distinguished as “inner intermediate layer” or “inner mantle layer”which terms are used interchangeably to refer to the intermediate ormantle layer nearest the core and furthest from the outer cover, asopposed to the “outer intermediate layer” or “outer mantle layer” whichterms are also used interchangeably to refer to the intermediate layerfurther from the core and closer to the outer cover, and as opposed tothe “intermediate layer” or “intermediate mantle layer” which terms arealso used interchangeably to refer to the intermediate layer between theinner intermediate layer and the outer intermediate layer.

The term “(meth)acrylic acid copolymers” is intended to mean copolymersof methacrylic acid and/or acrylic acid.

The term “(meth)acrylate” is intended to mean an ester of methacrylicacid and/or acrylic acid.

The term “partially neutralized” is intended to mean an ionomer with adegree of neutralization of less than 100 percent. The term “highlyneutralized” is intended to mean an ionomer with a degree ofneutralization of greater than 50 percent. The term “fully neutralized”is intended to mean an ionomer with a degree of neutralization of 100percent.

The term “prepolymer” as used herein is intended to mean any polymericmaterial that can be further processed to form a final polymer materialof a manufactured golf ball, such as, by way of example and notlimitation, a polymerized or partially polymerized material that canundergo additional processing, such as crosslinking.

The term “thermoplastic” as used herein is intended to mean a materialthat is capable of softening or melting when heated and of hardeningagain when cooled. Thermoplastic polymer chains often are notcross-linked or are lightly crosslinked using a chain extender, but theterm “thermoplastic” as used herein may refer to materials thatinitially act as thermoplastics, such as during an initial extrusionprocess or injection molding process, but which also may be crosslinked,such as during a compression molding step to form a final structure.

The term “thermoset” as used herein is intended to mean a material thatcrosslinks or cures via interaction with as crosslinking or curingagent. Crosslinking may be induced by energy, such as heat (generallyabove 200° C.), through a chemical reaction (by reaction with a curingagent), or by irradiation. The resulting composition remains rigid whenset, and does not soften with heating. Thermosets have this propertybecause the long-chain polymer molecules cross-link with each other togive a rigid structure. A thermoset material cannot be melted andre-molded after it is cured. Thus thermosets do not lend themselves torecycling unlike thermoplastics, which can be melted and re-molded.

The term “unimodal polymer” refers to a polymer comprising one mainfraction and more specifically to the form of the polymers molecularweight distribution curve, i.e., the molecular weight distribution curvefor the total polymer product shows only a single maximum.

The term “zwitterion” as used herein is intended to mean a form of thecompound having both an amine group and carboxylic acid group, whereboth are charged and where the net charge on the compound is neutral.

The present invention can be used in forming golf balls of any desiredsize. “The Rules of Golf” by the USGA dictate that the size of acompetition golf ball must be at least 1.680 inches in diameter;however, golf balls of any size can be used for leisure golf play. Thepreferred diameter of the golf balls is from about 1.680 inches to about1.800 inches. The more preferred diameter is from about 1.680 inches toabout 1.760 inches. A diameter of from about 1.680 inches to about 1.740inches is most preferred; however diameters anywhere in the range offrom 1.70 to about 2.0 inches can be used. Oversize golf balls withdiameters above about 1.760 inches to as big as 2.75 inches are alsowithin the scope of the invention.

In view of the advantages of injection molding versus the more complexcasting process, under some circumstances it is advantageous to haveformulations capable of curing as a thermoset but only within aspecified temperature range above that of the typical injection moldingprocess. This allows parts, such as golf ball cover layers, to beinitially injection molded, followed by subsequent processing at highertemperatures and pressures to induce further crosslinking and curing,resulting in thermoset properties in the final part. Such an initiallyinjection moldable composition is thus called a post-curable urethane orurea composition.

Polyurethane-Urea

In certain embodiments disclosed herein a cover or intermediate layer ofa golf ball is made from a thermoplastic polyurethane-urea (TPUU) or ablend composition comprising TPUU. The TPUU (or a TPUU-containing blendcomposition) can be post-curable composition. For example, the TPUU maybe crosslinked after the layer has been initially formed via injectionmolding.

In certain embodiments, the TPUU can be synthesized from an isocyanate,a polyol, and an amine chain extender. The TPUU can be thermallycrosslinked by adding any material that can react with urethane/ureagroups, remaining isocyanate/hydroxyl groups and/or double bonds in theTPUU. Non-limited examples of crosslinkers include an amine, a blockedamine, an isocyanate, a blocked isocyanate, a peroxide, asulfur-containing compound, and any combination of those. TheTPUU-containing composition can also optionally include fillers such asZnO and ZDA or fibers such as organic, inorganic, or metallic fillers orfibers in a continuous, non-continuous form, or any combination ofthose. The TPUU-containing composition can further optionally includecolorants, UV-stabilizer, and anti-oxidant, fluorescent-whitening agent,processing aids, and mold-release.

Conventional thermoplastic polyurethanes (TPUs) have only urethanelinkages in the main chain, and none of them used as a golf ball covermeet requirements due to the poor shear cut resistance. Instead of TPU,the presently disclosed urethane composition is polyurethane-urea whichhas both urethane and urea linkages in the main polymer chain and showsimproved shear cut resistance. Therefore, it would be desirable toincorporate urea groups into traditional TPU to improveabrasion/scratch/shear cut resistance. The thermoplasticpolyurethane-urea (TPUU) can be used as a cover without crosslinking, orit can be processed as a thermoplastic, and then chemically crosslinkedto have thermoset characteristics if needed.

Disclosed herein are golf balls having cover and/or intermediate layersincorporating TPUU compositions. Specifically, these compositionsincorporate a thermally crosslinked TPUU. The resulting reaction productincorporates a crosslinked structure that provides for excellent ballproperties. The present invention also resides in methods for makinggolf balls incorporating this reaction product. Because the originalurethane is thermoplastic, the material can be prepared with ease ofprocessing, while the crosslinked structure of the reaction productprovides for improved ball properties. The compositions incorporatingthis reaction product are easy to use, and they provide flexibility ingolf ball design to improve ball performance, such as hit feel and spinrate, without adversely affecting shear-cut resistance of the ball.

Also disclosed herein is a method for preparing a golf ball layer thatincludes: (1) preparing a composition that includes a thermoplasticpolyurethane-urea that is the reaction product of (a) a diol or polyol,(b) a first isocyanate, and (c) an amine chain extender; (2) and theninducing crosslinking or polymerization in the composition by adding acrosslinker to the composition. The crosslinker may be added to thecomposition by dry blending, extrusion or other mixing methods beforeinjection molding. In certain embodiments, the TPUU composition can becrosslinked by heating the composition at a temperature of at least 100°C., more particularly at least 120° C., and most particularly at least140° C. In certain embodiments, the composition is not heated to atemperature greater than 250° C., more particularly not greater than240° C., and most particularly not greater than 230° C. In preferredaspects of the method, forming the TPUU composition into a layerincludes injection molding the composition to form the layer. The TPUUcomposition can be prepared by dry-blending the composition, or mixingthe composition using a mill, internal mixer or extruder, as well asintroducing into the composition ionomeric polymer, non-ionomericpolymer, polyamide, silicone, styrenic-copolymers, or mixtures of these.

In a preferred aspect of the method, preparing the TPUU-containingcomposition and forming the composition into a layer take place underconditions of temperature and pressure such that substantially nocrosslinking occurs in the composition during these steps. In apreferred aspect of the method, forming a layer incorporates forming thecomposition into half cups, and then positioning the half cups a golfball core, so that the half cups form a layer and the inner core isenclosed by this layer. In certain embodiments, forming theTPUU-containing composition into a layer utilizes reaction molding,casting, or injection molding.

The various possible components of the compositions can be mixedtogether, with or without melting them. Dry blending equipment, such asa tumbler mixer. V-blender, or ribbon blender, can be used to preparethe composition. Materials can be added to the composition using a mill,internal mixer, extruder or combinations of these, with or withoutapplication of thermal energy to produce melting. The additionalmaterials also can be added to a color concentrate, which then is addedto the composition to impart a white color to golf ball. Any combinationof the above-mentioned mixing methods can be used to produce a finalcomposition.

A preferred method involves injection molding a core, intermediatelayer, or cover of the composition into a cold mold without inducingheavy crosslinking. The product from this process then iscompression-molded to induce partial or full crosslinking by use ofthermal energy. The crosslinker is added via injection molding,extrusion, or other mixing methods. In another preferred method,injection molding is used to inject the composition around a corepositioned in a mold, and crosslinking occurs during the injectionmolding process. In yet another preferred method, an intermediate layeror a cover of the composition can be prepared by injection moldinghalf-shells. The half shells are then positioned around a core andcompression molded. The heat and pressure first melt the composition toseal the two half shells together to form a complete layer. Crosslinkingoccurs during compression molding process.

The crosslink density (i.e., the degree of crosslinking) of thecompositions of the present invention can be adjusted by varying theamount or type of crosslinker in the composition. The crosslink densityalso is controlled by the temperature to which the composition isbrought during processing. Preferably, the ratio by weight of thethermoplastic polyurethane-precursor to that of the crosslinker used inthe composition ranges between 99.9:0.1 and about 60:40, more preferablybetween 99.9:0.1 and about 65:35, even more preferably between about98:2 and about 70:30, and most preferably between about 98:2 and about75:25.

There are two basic techniques that can be used to make thepolyurethane-urea compositions: a) one-shot technique, and b) prepolymeror two-shot technique. In the one-shot technique, the isocyanate,polyol, and amine-terminated chain extender are reacted in one step.

The prepolymer technique involves a first reaction between theisocyanate and polyol compounds to produce a polyurethane prepolymer,and a subsequent reaction between the prepolymer and amine-terminatedchain extender. As a result of the reaction between the isocyanate andpolyol compounds, there will be some unreacted NCO groups in thepolyurethane prepolymer. The prepolymer should have less than 14%unreacted NCO groups. Preferably, the prepolymer has no greater than8.5% unreacted NCO groups, more preferably from 2.5% to 8%, and mostpreferably from 5.0% to 8.0% unreacted NCO groups. As the weight percentof unreacted isocyanate groups increases, the hardness of thecomposition also generally increases

When the polyurethane prepolymer is reacted with an amine-terminatedchain extender during the chain-extending step, any excess isocyanategroups in the prepolymer will react with the amine groups in the curingagent and create urea linkages having the following general structure:

where x is the chain length, i.e., about 1 or greater, and R and R₁ arestraight chain or branched hydrocarbon chain having about 1 to about 20carbons.

This chain-extending step, which occurs when the polyurethane prepolymeris reacted with amine-terminated chain extenders, builds-up themolecular weight and extends the chain length of the prepolymer. Whenthe polyurethane prepolymer is reacted with hydroxyl-terminated chainextenders, a polyurethane composition having urethane linkages isproduced.

When the polyurethane prepolymer is reacted with amine-terminated chainextenders, a polyurethane-urea composition having urethane and urealinkages is produced. The polyurethane-urea composition is distinct fromthe pure polyurethane composition. The concentration of urethane andurea linkages in the composition may vary. In general, the compositionmay contain a mixture of about 10 to 90 wt. % urethane and about 90% to10 wt. % urea linkages. The resulting polyurethane-urea composition haselastomeric properties based on phase separation of the soft and hardsegments. The soft segments, which are formed from the polyol reactants,are generally flexible and mobile, while the hard segments, which areformed from the isocyanate and chain extenders, are generally stiff andimmobile.

A catalyst may be employed to promote the reaction between theisocyanate and polyol compounds for producing the prepolymer or betweenprepolymer and chain extender during the chain-extending step.Preferably, the catalyst is added to the reactants before producing theprepolymer. Suitable catalysts include, but are not limited to, bismuthcatalyst; zinc octoate; stannous octoate; tin catalysts such asbis-butyltin dilaurate, bis-butyltin diacetate, stannous octoate; tin(II) chloride, tin (IV) chloride, bis-butyltin dimethoxide,dimethyl-bis[1-oxonedecyl)oxy]stannane, di-n-octyltin bis-isooctylmercaptoacetate; amine catalysts such as triethylenediamine,triethylamine, and tributylamine; organic acids such as oleic acid andacetic acid; delayed catalysts; and mixtures thereof. The catalyst ispreferably added in an amount sufficient to catalyze the reaction of thecomponents in the reactive mixture. In one embodiment, the catalyst ispresent in an amount from about 0.001 percent to about 1 percent, andpreferably 0.1 to 0.5 percent, by weight of the composition.

Isocyanates suitable for use in the compositions and method disclosedherein include: trimethylene diisocyanate, tetramethylene diisocyanate,pentamethylene diisocyanate, hexamethylene diisocyanate, ethylenediisocyanate, diethylidene diisocyanate, propylene diisocyanate,butylenes diisocyanate, bitolylene diisocyanate, tolidine isocyanate,isophorone diisocyanate, dimeryl diisocyanate,dodecane-1,12-diisocyanate, 1,10-decamethylene diisocyanate,cyclohexylene-1,2-diisocyanate, 1,10-decamethylene diisocyanate,1-chlorobenzene-2,4-diisocyanate, furfurylidene diisocyanate,2,4,4-trimethyl hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, dodecamethylene diisocyanate,1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate,1,3-cyclobutane diisocyanate, 1,4-cyclohexane diisocyanate,4,4′-methylenebis(cyclohexyl isocyanate), 4,4′-methylenebis(phenylisocyanate), 1-methyl-2,4-cyclohexane diisocyanate,1-methyl-2,6-cyclohexane diisocyanate, 1,3-bis(isocyanato-methyl)cyclohexane,1,6-diisocyanato-2,2,4,4-tetra-methylhexane,1,6-diisocyanato-2,4,4-tetra-trimethylhexane,trans-cyclohexane-1,4-diisocyanate,3-isocyanato-methyl-3,5,5-trimethylcyclo-hexyl isocyanate,1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, cyclo-hexylisocyanate, dicyclohexylmethane 4,4′-diisocyanate,1,4-bis(isocyanatomethyl) cyclohexane, m-phenylene diisocyanate,m-xylylene diisocyanate, m-tetramethylxylylene diisocyanate, p-phenylenediisocyanate, p,p′-biphenyl diisocyanate, 3,3′-dimethyl-4,4′-biphenylenediisocyanate, 3,3′-dimethoxy-4,4′-biphenylene diisocyanate,3,3′-diphenyl-4,4′-biphenylene diisocyanate, 4,4′-biphenylenediisocyanate, 3,3′-dichloro-4,4′-biphenylene diisocyanate,1,5-naphthalene diisocyanate, 4-chloro-1,3-phenylene diisocyanate,1,5-tetrahydronaphthalene diisocyanate, metaxylene diisocyanate,2,4-toluene diisocyanate, 2,4′-diphenylmethane diisocyanate,2,4-chlorophenylene diisocyanate, 4,4′-diphenylmethane diisocyanate,p,p′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate,2,6-tolylene diisocyanate, 2,2-diphenylpropane-4,4′-diisocyanate,4,4′-toluidine diisocyanate, dianidine diisocyanate, 4,4′-diphenyl etherdiisocyanate, 1,3-xylylene diisocyanate, 1,4-naphthylene diisocyanate,azobenzene-4,4′-diisocyanate, diphenyl sulfone-4,4′-diisocyanate,triphenylmethane 4,4,4″-triisocyanate, isocyanatoethyl methacrylate,3-isopropenyl-α,α-dimethylbenzyl-isocyanate, dichlorohexamethylenediisocyanate, ω,ω′-diisocyanato-1,4-diethylbenzene, polymethylenepolyphenylene polyisocyanate, isocyanurate modified compounds, andcarbodiimide modified compounds, as well as biuret modified compounds ofthe above polyisocyanates. These isocyanates may be used either alone orin combination. These combination isocyanates include triisocyanates,such as biuret of hexamethylene diisocyanate and triphenylmethanetriisocyanates, and polyisocyanates, such as polymeric diphenylmethanediisocyanate. These isocyanates may be used for making thepolyurethane-urea precursor composition and/or as the second isocyanatefor crosslinking the polyurethane-urea precursor composition. In certainembodiments, the isocyanate used for the making the polyurethane-ureaprecursor composition and the second isocyanate used for crosslinkinghave the same composition or a different composition.

Organic peroxides may provide additional crosslinking in thecomposition. Examples of suitable peroxides include aliphatic peroxides,aromatic peroxides, cyclic peroxides, or mixtures of these. Primary,secondary, or tertiary peroxides can be used, with tertiary peroxidespreferred.

Polyamines suitable for use in the compositions include primary,secondary and tertiary amines having two or more amines as functionalgroups. Polyamines suitable for use in the compositions of the presentinvention include, but are not limited to, amine-terminatedhydrocarbons, amine-terminated polyethers, amine-terminated polyesters,amine-terminated polycaprolactones, amine-terminated polycarbonates,amine-terminated polyamides, and mixtures thereof. The amine-terminatedcompound may be a polyether amine selected from polytetramethylene etherdiamines, polyoxypropylene diamines, poly(ethylene oxide cappedoxypropylene) ether diamines, triethyleneglycoldiamines, propyleneoxide-based triamines, trimethylolpropane-based triamines,glycerin-based triamines, and mixtures thereof.

Exemplary diamines include aliphatic diamines, such astetramethylenediamine, pentamethylenediamine, hexamethylenediamine;alicyclic diamines, such as 3,3′-dimethyl-4,4′-diamino-dicyclohexylmethane; or aromatic diamines, such as diethyl-2,4-toluenediamine,4,4″-methylenebis-(3-chloro,2,6-diethyl)-aniline (available from AirProducts and Chemicals Inc., of Allentown, Pa., under the trade nameLONZACURE®), 3,3′-dichlorobenzidene; 3,3′-dichloro-4,4′-diaminodiphenylmethane (MOCA); N,N,N′,N′-tetrakis(2-hydroxypropyl) ethylenediamine,3,5-dimethylthio-2,4-toluenediamine;3,5-dimethylthio-2,6-toluenediamine; N,N′-dialkyldiamino diphenylmethane; trimethylene-glycol-di-p-aminobenzoate;polytetramethyleneoxide-di-p-aminobenzoate, 4,4′-methylenebis-2-chloroaniline, 2,2′,3,3′-tetrachloro-4,4′-diamino-phenyl methane,p,p′-methylenedianiline, p-phenylenediamine or 4,4′-diaminodiphenyl; and2,4,6-tris(dimethylaminomethyl) phenol.

Also included as possible crosslinking agents are the blocked polyamineswhich can include those amine carbamate salts formed by reacting of theamines. Other preferred crosslinking agents include various ketimines oraldimines which are known to the art and to the literature. Suchcompounds are generally prepared by reacting a polyamine with either aketone or an aldehyde. Examples of specific ketimine compounds which canbe utilized are set forth in U.S. Pat. No. 4,507,443, the entire contentof which is hereby fully incorporated by reference. These blockedcuratives react slowly in the absence of moisture, but unblock duringapplication to form a polyamine and a volatile ketone.

Also included are complexes of polyamines with salts. These complexesare virtually non-reactive at room temperature but when heated the saltcomplex unblocks and the freed polyamine. The metal salts can be anysuitable metal salt, including alkali, alkaline earth, transition metal,and main group metal salts. Particularly preferred are the alkali andalkaline metal salts. Some examples of suitable alkali metal saltsinclude those metal salts formed by combination of any of lithium,sodium, potassium, or rubidium with any of fluoride, chloride, bromide,or iodide. A particularly preferred alkali metal salt is sodiumchloride. Some examples of suitable alkaline earth metal salts includethose metal salts formed by combination of any of magnesium, calcium,strontium, or barium with any of fluoride, chloride, bromide, or iodide.Salt complexes of methylenedianiline are commercially available, underthe trade name Caytur® from Chemtura Corporation including Caytur 21DAand 31 DA which are complexes of methylene dianiline (MDA) and sodiumchloride dispersed in dioctyl adipate, and Caytur 21 an 31 which arecomplexes of methylene dianiline (MDA) and sodium chloride dispersed indioctyl phthalate.

Suitable amine-terminated chain-extending agents that can be used inchain-extending the polyurethane-urea composition (e.g., chain extendinga polyurethane prepolymer) include, but are not limited to, unsaturateddiamines such as 4,4′-diamino-diphenylmethane (i.e.,4,4′-methylene-dianiline or “MDA”), m-phenylenediamine,p-phenylenediamine, 1,2- or 1,4-bis(sec-butylamino)benzene,3,5-diethyl-(2,4- or 2,6-)toluenediamine or “DETDA”,3,5-dimethylthio-(2,4- or 2,6-)toluenediamine, 3,5-diethylthio-(2,4- or2,6-)toluenediamine, 3,3′-dimethyl-4,4′-diamino-diphenylmethane,3,3′-diethyl-5,5′-dimethyl4,4′-diamino-diphenylmethane (i.e.,4,4′-methylene-bis(2-ethyl-6-methyl-benezeneamine)),3,3′-dichloro-4,4′-diamino-diphenylmethane (i.e.,4,4′-methylene-bis(2-chloroaniline) or “MOCA”),3,3′,5,5′-tetraethyl-4,4′-diamino-diphenylmethane (i.e.,4,4′-methylene-bis(2,6-diethylaniline),2,2′-dichloro-3,3′5,5′-tetraethyl-4,4′-diamino-diphenylmethane (i.e.,4,4′-methylene-bis(3-chloro-2,6-diethyleneaniline) or “MCDEA”),3,3′-diethyl-5,5′-dichloro-4,4′-diamino-diphenylmethane, or “MDEA”),3,3′-dichloro-2,2′,6,6′-tetraethyl-4,4′-diamino-diphenylmethane,3,3′-dichloro-4,4′-diamino-diphenylmethane,4,4′-methylene-bis(2,3-dichloroaniline) (i.e.,2,2′,3,3′-tetrachloro-4,4′-diamino-diphenylmethane or “MDCA”),4,4′-bis(sec-butylamino)-diphenylmethane,N,N′-dialkylamino-diphenylmethane,trimethyleneglycol-di(p-aminobenzoate),polyethyleneglycol-di(p-aminobenzoate),polytetramethyleneglycol-di(p-aminobenzoate); saturated diamines such asethylene diamine, 1,3-propylene diamine, 2-methyl-pentamethylenediamine, hexamethylene diamine, 2,2,4- and 2,4,4-trimethyl-1,6-hexanediamine, imino-bis(propylamine), imido-bis(propylamine),methylimino-bis(propylamine) (i.e.,N-(3-aminopropyl)-N-methyl-1,3-propanediamine),1,4-bis(3-aminopropoxy)butane (i.e.,3,3′-[1,4-butanediylbis-(oxy)bis]-1-propanamine),diethyleneglycol-bis(propylamine) (i.e.,diethyleneglycol-di(aminopropyl)ether),4,7,10-trioxatridecane-1,13-diamine, 1-methyl-2,6-diamino-cyclohexane,1,4-diamino-cyclohexane, poly(oxyethylene-oxypropylene)diamines, 1,3- or1,4-bis(methylamino)-cyclohexane, isophorone diamine, 1,2- or1,4-bis(sec-butylamino)-cyclohexane, N,N′-diisopropyl-isophoronediamine, 4,4′-diamino-dicyclohexylmethane,3,3′-dimethyl-4,4′-diamino-dicyclohexylmethane,3,3′-dichloro-4,4′-diamino-dicyclohexylmethane,N,N′-dialkylamino-dicyclohexylmethane, polyoxyethylene diamines,3,3′-diethyl-5,5′-dimethyl-4,4′-diamino-dicyclohexylmethane,polyoxypropylene diamines,3,3′-diethyl-5,5′-dichloro-4,4′-diamino-dicyclohexylmethane,polytetramethylene ether diamines,3,3′,5,5′-tetraethyl-4,4′-diamino-dicyclohexylmethane (i.e.,4,4′-methylene-bis(2,6-diethylaminocyclohexane)),3,3′-dichloro-4,4′-diamino-dicyclohexylmethane,2,2′-dichloro-3.3′,5,5′-tetraethyl-4,4′-diamino-dicyclohexylmethane.(ethylene oxide)-capped polyoxypropylene ether diamines,2,2′,3,3′-tetrachloro-4,4′-diamino-dicyclohexylmethane,4,4′-bis(sec-butylamino)-dicyclohexylmethane; triamines such asdiethylene triamine, dipropylene triamine, (propylene oxide)-basedtriamines (i.e., polyoxypropylene triamines),N-(2-aminoethyl)-1,3-propylenediamine (i.e., N₃-amine), glycerin-basedtriamines, (all saturated); tetramines such asN,N′-bis(3-aminopropyl)ethylene diamine (i.e., N₄-amine) (bothsaturated), triethylene tetramine; and other polyamines such astetraethylene pentamine (also saturated). The amine agents used as chainextenders normally have a cyclic structure and a low molecular weight(250 or less). More preferably, the amine-terminated agent can beselected from the group consisting of: 1,3-propane diamine, 1,4-butanediamine, 1,5-pentane diamine, 1,6-hexane diamine, 1,7-heptane diamine,1,8-octane diamine, 1,9-nonane diamine, 1,10-decane diamine,1,11-undecane diamine, and 1,12-dodecane diamine,polymethylene-di-p-aminobenzoates,polyethyleneglycol-bis(4-aminobenzoates), polytetramethyleneetherglycol-di-p-aminobenzoate, polypropyleneglycol-di-p-aminobenzoate,and mixtures thereof.

Polyols suitable for use in the compositions of the present inventioninclude polyester polyols, polyether polyols, polycarbonate polyols andpolybutadiene polyols.

Polyester polyols are prepared by condensation or step-growthpolymerization utilizing diacids. Primary diacids for polyester polyolsare adipic acid and isomeric phthalic acids. Adipic acid is used formaterials requiring added flexibility, whereas phthalic anhydride isused for those requiring rigidity. Some examples of polyester polyolsinclude poly(ethylene adipate) (PEA), poly(diethylene adipate) (PDA),poly(propylene adipate) (PPA), poly(tetramethylene adipate) (PBA),poly(hexamethylene adipate) (PHA), poly(neopentylene adipate) (PNA),polyols composed of 3-methyl-1,5-pentanediol and adipic acid, randomcopolymer of PEA and PDA, random copolymer of PEA and PPA, randomcopolymer of PEA and PBA, random copolymer of PHA and PNA, caprolactonepolyol obtained by the ring-opening polymerization of ε-caprolactone,and polyol obtained by opening the ring of β-methyl-δ-valerolactone withethylene glycol can be used either alone or in a combination thereofAdditionally, polyester polyol may be composed of a copolymer of atleast one of the following acids and at least one of the followingglycols. The acids include terephthalic acid, isophthalic acid, phthalicanhydride, oxalic acid, malonic acid, succinic acid, pentanedioic acid,hexanedioic acid, octanedioic acid, nonanedioic acid, adipic acid,azelaic acid, sebacic acid, dodecanedioic acid, dimer acid (a mixture),ρ-hydroxybenzoate, trimellitic anhydride, ε-caprolactone, andβ-methyl-δ-valerolactone. The glycols includes ethylene glycol,propylene glycol, butylene glycol, pentylene glycol, 1,4-butanediol,1,5-pentanediol, 1,6-hexanediol, neopentylene glycol, polyethyleneglycol, polytetramethylene glycol, 1,4-cyclohexane dimethanol,pentaerythritol, and 3-methyl-1,5-pentanediol.

Polyether polyols are prepared by the ring-opening additionpolymerization of an alkylene oxide (e.g. ethylene oxide and propyleneoxide) with an initiator of a polyhydric alcohol (e.g. diethyleneglycol), which is an active hydride. Specifically, polypropylene glycol(PPG), polyethylene glycol (PEG) or propylene oxide-ethylene oxidecopolymer can be obtained. Polytetramethylene ether glycol (PTMG) isprepared by the ring-opening polymerization of tetrahydrofuran, producedby dehydration of 1,4-butanediol or hydrogenation of furan.Tetrahydrofuran can form a copolymer with alkylene oxide. Specifically,tetrahydrofuran-propylene oxide copolymer or tetrahydrofuran-ethyleneoxide copolymer can be formed. The polyether polyol may be used eitheralone or in a combination. Polycarbonate polyol is obtained by thecondensation of a known polyol (polyhydric alcohol) with phosgene,chloroformic acid ester, dialkyl carbonate or diallyl carbonate.Particularly preferred polycarbonate polyol contains a polyol componentusing 1,6-hexanediol, 1,4-butanediol, 1,3-butanediol, neopentylglycol or1,5-pentanediol. Polycarbonate polyols can be used either alone or in acombination with other polyols.

Polybutadiene polyol includes liquid diene polymer containing hydroxylgroups having an average of at least 1.7 functional groups, and may becomposed of diene polymer or diene copolymer having 4 to 12 carbonatoms, or a copolymer of such diene with addition to polymerizableα-olefin monomer having 2 to 2.2 carbon atoms. Specific examples includebutadiene homopolymer, isoprene homopolymer, butadiene-styrenecopolymer, butadiene-isoprene copolymer, butadiene-acrylonitrilecopolymer, butadiene-2-ethyl hexyl acrylate copolymer, andbutadiene-n-octadecyl acrylate copolymer. These liquid diene polymerscan be obtained, for example, by heating a conjugated diene monomer inthe presence of hydrogen peroxide in a liquid reactant.

The compositions disclosed herein also may include plasticizers.Examples of suitable plasticizers include: dioctyl phthalate (DOP),dibutyl phthalate (DBP), dioctyl adipate (DOA), triethylene glycoldibenzoate, tricresyl phosphate, dioctyl phthalate, aliphatic ester ofpentaerythritol, dioctyl sebacate, and diisooctyl azelate. In additionto the material discussed above, the compositions disclosed herein canincorporate one or more polymers in addition to the thermoplasticpolyurethane-urea and crosslinking agent. These additional polymers maybe added as need for a desired effect, such as softening an otherwiseoverly hard cover composition. Examples of suitable additional polymersinclude, but are not limited to, the following: thermoplastic elastomer,thermoset elastomer, synthetic rubber, thermoplastic vulcanizate,copolymeric ionomer, terpolymeric ionomer, polycarbonate, polyolefin,polyamide, copolymeric polyamide, polyesters, polyvinyl alcohols,acrylonitrile-butadiene-styrene copolymers, polyarylate, polyacrylate,polyphenyl ether, modified-polyphenyl ether, high-impact polystyrene,diallyl phthalate polymer, metallocene catalyzed polymers,acrylonitrile-styrene-butadiene (ABS), styrene-acrylonitrile (SAN)(including olefin-modified SAN and acrylonitrile styrene acrylonitrile),styrene-maleic anhydride (S/MA) polymer, styrenic copolymer,functionalized styrenic copolymer, functionalized styrenic terpolymer,styrenic terpolymer, cellulose polymer, liquid crystal polymer (LCP),ethylene-propylene-diene terpolymer (EPDM), ethylene-vinyl acetatecopolymers (EVA), ethylene-propylene copolymer, ethylene vinyl acetate,polyurea, and polysiloxane or any metallocene-catalyzed polymers ofthese species. Particularly suitable plasticizers for use in thecompositions within the scope of the present invention include:polyethylene-terephthalate, polybutyleneterephthalate,polytrimethylene-terephthalate, ethylene-carbon monoxide copolymer,polyvinyl-diene fluorides, polyphenylenesulfide, polypropylene-oxide,polyphenyloxide, polypropylene, functionalized polypropylene,polyethylene, ethylene-octene copolymer, ethylene-methyl acrylate,ethylene-butyl acrylate, polycarbonate, polysiloxane, functionalizedpolysiloxane, copolymeric ionomer, terpolymeric ionomer, polyetheresterelastomer, polyesterester elastomer, polyetheramide elastomer,propylene-butadiene copolymer, modified copolymer of ethylene andpropylene, styrenic copolymer (including styrenic block copolymer andrandomly distributed styrenic copolymer, such as styrene-isobutylenecopolymer and styrene-butadiene copolymer), partially or fullyhydrogenated styrene-butadiene-styrene block copolymers such asstyrene-(ethylene-propylene)-styrene orstyrene-(ethylene-butylene)-styrene block copolymers, partially or fullyhydrogenated styrene-butadiene-styrene block copolymers with functionalgroup, polymers based on ethylene-propylene-(diene), polymers based onfunctionalized ethylene-propylene-(diene), dynamically vulcanizedpolypropylene/ethylene-propylene-diene-copolymer, thermoplasticvulcanizates based on ethylene-propylene-(diene), natural rubber,styrene-butadiene rubber, nitrile rubber, chloroprene rubber,fluorocarbon rubber, butyl rubber, acrylic rubber, silicone rubber,chlorosulfonated polyethylene, polyisobutylene, alfin rubber, polyesterrubber, epichlorphydrin rubber, chlorinated isobutylene-isoprene rubber,nitrile-isobutylene rubber, 1,2-polybutadiene, 1,4-polybutadiene,cis-polyisoprene, trans-polyisoprene, and polybutylene-octene.

Suitable polyamides for use as an additional material in thecompositions also include resins obtained by: (1) polycondensation of(a) a dicarboxylic acid, such as oxalic acid, adipic acid, sebacic acid,terephthalic acid, isophthalic acid or 1,4-cyclohexylidicarboxylic acid,with (b) a diamine, such as ethylenediamine, tetramethylenediamine,pentamethylenediamine, hexamethylene-diamine or decamethylenediamine,1,4-cyclohexyldiamine or m-xylylenediamine; (2) a ring-openingpolymerization of cyclic lactam, such as ε-caprolactam or ω-laurolactam;(3) polycondensation of an aminocarboxylic acid, such as 6-amino caproicacid, 9-aminononaoic acid, 11-aminoudecanoic acid or 12-aminododecanoicacid; or, (4) copolymerization of a cyclic lactam with a dicarboxylicacid and a diamine. Specific examples of suitable polyamides includeNylon 6, Nylon 66, Nylon 610, Nylon 11, Nylon 12, copolymerized Nylon,Nylon MXD6, and Nylon 46. Other preferred materials suitable for use asan additional material in compositions within the scope of the presentinvention include polyester elastomers marketed under the name SKYPEL bySK Chemicals of South Korea, or triblock copolymers marketed under thename HG-252 by Kuraray Corporation of Kurashiki, Japan. These triblockcopolymers have at least one polymer block comprising an aromatic vinylcompound and at least one polymer block comprising a conjugated dienecompound, and a hydroxyl group at a block copolymer. The materialslisted above all can provide for particular enhancements to ball layersprepared within the scope of the present invention.

Ionomeric polymers often are found in covers and intermediate layers ofgolf balls. These ionomers also are well suited for blending intocompositions disclosed herein. Suitable ionomeric polymers (i.e.,copolymer- or terpolymer-type ionomers) include α-olefin/unsaturatedcarboxylic acid copolymer-type ionomeric or terpolymer-type ionomericresins that can be described as copolymer E/X/Y, where E representsethylene, X represents a softening comonomer such as acrylate ormethacrylate, and Y is acrylic or methacrylic acid. The acid moiety of Yis neutralized to form an ionomer by a cation such as lithium, sodium,potassium, magnesium, calcium, barium, lead, tin, zinc or aluminum.Also, a combination of such cations is used for the neutralization.Copolymeric ionomers are obtained by neutralizing at least portion ofcarboxylic groups in a copolymer of an α-olefin and an α,β-unsaturatedcarboxylic acid having 3 to 8 carbon atoms, with a metal ion. Examplesof suitable α-olefins include ethylene, propylene, 1-butene, and1-hexene. Examples of suitable unsaturated carboxylic acids includeacrylic, methacrylic, ethacrylic, alphachloroacrylic, crotonic, maleic,fumaric, and itaconic acid. Copolymeric ionomers include ionomers havingvaried acid contents and degrees of acid neutralization, neutralized bymonovalent or bivalent cations discussed above.

Terpolymeric ionomers are obtained by neutralizing at least portion ofcarboxylic groups in a terpolymer of an α-olefin, and an α,β-unsaturatedcarboxylic acid having 3 to 8 carbon atoms and an α,β-unsaturatedcarboxylate having 2 to 22 carbon atoms with metal ion.

Examples of suitable α-olefins include ethylene, propylene, 1-butene,and 1-hexene. Examples of suitable unsaturated carboxylic acids includeacrylic, methacrylic, ethacrylic, alphachloroacrylic, crotonic, maleic,fumaric, and itaconic acid. Terpolymeric ionomers include ionomershaving varied acid contents and degrees of acid neutralization,neutralized by monovalent or bivalent cations discussed above. Examplesof suitable ionomeric resins include those marketed under the nameSURLYN manufactured by E.I. DuPont de Nemours & Company of Wilmington,Del., and IOTEK manufactured by Exxon Mobil Corporation of Irving, Tex.

Silicone materials also are well suited for blending into compositionsdisclosed herein. These can be monomers, oligomers, prepolymers, orpolymers, with or without additional reinforcing filler. One type ofsilicone material that is suitable can incorporate at least 1 alkenylgroup having at least 2 carbon atoms in their molecules. Examples ofthese alkenyl groups include, but are not limited to, vinyl, allyl,butenyl, pentenyl, hexenyl and decenyl. The alkenyl functionality can belocated at any location of the silicone structure, including one or bothterminals of the structure. The remaining (i.e., non-alkenyl)silicon-bonded organic groups in this component are independentlyselected from hydrocarbon or halogenated hydrocarbon groups that containno aliphatic unsaturation. Non-limiting examples of these include: alkylgroups, such as methyl, ethyl, propyl, butyl, pentyl and hexyl;cycloalkyl groups, such as cyclohexyl and cycloheptyl; aryl groups suchas phenyl, tolyl and xylyl; aralkyl groups, such as benzyl andphenethyl; and halogenated alkyl groups, such as 3,3,3-trifluoropropyland chloromethyl. Another type of silicone material suitable for use inthe present invention is one having hydrocarbon groups that lackaliphatic unsaturation. Specific examples of suitable silicones for usein making compositions of the present invention include the following:trimethylsiloxy-endblocked dimethylsiloxane-methylhexenylsiloxanecopolymers; dimethylhexenlylsiloxy-endblockeddimethylsiloxane-methylhexenylsiloxane copolymers;trimethylsiloxy-endblocked dimethylsiloxane-methylvinylsiloxanecopolymers; trimethylsiloxy-endblockedmethylphenylsiloxane-dimethylsiloxane-methylvinylsiloxane copolymers;dimethylvinylsiloxy-endblocked dimethylpolysiloxanes;dimethylvinylsiloxy-endblocked dimethylsiloxane-methylvinylsiloxanecopolymers; dimethylvinylsiloxy-endblocked methylphenylpolysiloxanes;dimethylvinylsiloxy-endblockedmethylphenylsiloxane-dimethylsiloxane-methylvinylsiloxane copolymers;and, the copolymers listed above, in which at least one end group isdimethylhydroxysiloxy. Commercially available silicones suitable for usein compositions within the scope of the present invention includeSilastic by Dow Corning Corp. of Midland. Mich., Blensil by GE Siliconesof Waterford, N.Y. and Elastosil by Wacker Silicones of Adrian, Mich.

Other types of copolymers also may be added to the compositionsdisclosed herein. Examples of copolymers comprising epoxy monomers andwhich are suitable for use within the scope of the present inventioninclude styrene-butadiene-styrene block copolymers, in which thepolybutadiene block contains epoxy group, and styrene-isoprene-styreneblock copolymers, in which the polyisoprene block contains epoxy.Commercially available examples of these epoxy functional copolymersinclude ESBS A1005, ESBS A1010, ESBS A1020, ESBS AT018, and ESBS AT019,marketed by Daicel Chemical Industries, Ltd.

The compositions disclosed herein also can include, in suitable amounts,one or more additional ingredients generally employed in golf balls andball compositions. Agents provided to achieve specific functions, suchas additives and stabilizers, can be present. Suitable ingredientsinclude colorants, UV stabilizers, photostabilizers, antioxidants,colorants, dispersants, mold releasing agents, processing aids, andfillers. The compositions can incorporate, for example, inorganicfillers, such as titanium dioxide, calcium carbonate, zinc sulfide orzinc oxide. Additional fillers can be chosen to impart additionaldensity to the compositions, such as zinc oxide, barium sulfate,tungsten or any other metallic powder having density higher than that ofthe base polymeric resin. Any organic or inorganic fibers, eithercontinuous or non-continuous, also can be in the compositions. Anexample of these is silica-reinforcing filler. This filler preferably isselected from finely divided, heat-stable minerals, such as fumed andprecipitated forms of silica, silica aerogels and titanium dioxidehaving a specific surface area of at least about 10 m²/gram.

In several embodiments, the TPUU constitutes the majority component ofan intermediate layer and/or cover layer. In particular, the TPUUconstitutes greater than 40 weight %, more preferably greater than 45weight %, and most preferably greater than 50 weight %, of the totalweight of the materials forming the intermediate and/or cover layer.

UV-Curable Polyurethane

In another embodiment ultraviolet-curable thermoplastic polyurethanes(UTPUs) can be used for making a cover layer and/or intermediate layerin a golf ball. The UTPUs have functional group(s) that are activatedwith a UV initiator when subjected to UV irradiation and formedcrosslinked material. The preferred example of a UV-activatablefunctional group is a (meth)acrylic group. The UTPUs can be processed(e.g., injection molded) as a thermoplastic and then crosslinked via UVirradiation to have thermoset characteristics. A cover and/orintermediate layer may be made from UV curable thermoplasticpolyurethane (UTPU) or UTPU-containing blend composition. The UTPU maybe a post-curable polyurethane.

In certain embodiments the UV intensity for UV curing of the compositionis >0.2 J/cm², more particularly greater than 1 J/cm², and mostparticularly greater than 3 J/cm². In certain embodiments the UVintensity for UV curing of the composition is not greater than 20 J/cm²,more particularly not greater than 15 J/cm², and most particularly notgreater than 10 J/cm².

In certain embodiments the UV curing of a golf ball layer can occur orbe completed during injection molding or post injection molding process.

In certain embodiments the UV curing of a golf ball layer can occur orbe completed during compression molding or post compression moldingprocess.

In certain embodiments golf balls may be produced by making half cups byinjection molding the UVPU, and then compression molding the resultingstructure to make a spherical layer of the golf ball with dimples ifnecessary, making a portion of the golf ball by injection molding theUVPU, preferably forming dimples on an outer surface of the portion, ormaking a dimpless golf ball by injection molding the UVPU and thenforming dimples on an outer surface of the portion during compressionmolding.

The UV-activatable functionalized thermoplastic polyurethane may be madefrom (i) an isocyanate, (ii) a diol or polyol and, optionally, (iii) achain extender.

Polyols suitable for use in the compositions of the present inventioninclude polyester polyols, polyether polyols, polycarbonate polyols andpolybutadiene polyols.

Polyester polyols are prepared by condensation or step-growthpolymerization utilizing diacids. Primary diacids for polyester polyolsare adipic acid and isomeric phthalic acids. Adipic acid is used formaterials requiring added flexibility, whereas phthalic anhydride isused for those requiring rigidity. Some examples of polyester polyolsinclude poly(ethylene adipate) (PEA), poly(diethylene adipate) (PDA),poly(propylene adipate) (PPA), poly(tetramethylene adipate) (PBA),poly(hexamethylene adipate) (PHA), poly(neopentylene adipate) (PNA),polyols composed of 3-methyl-1,5-pentanediol and adipic acid, randomcopolymer of PEA and PDA, random copolymer of PEA and PPA, randomcopolymer of PEA and PBA, random copolymer of PHA and PNA, caprolactonepolyol obtained by the ring-opening polymerization of ε-caprolactone,and polyol obtained by opening the ring of β-methyl-δ-valerolactone withethylene glycol can be used either alone or in a combination thereof.Additionally, polyester polyol may be composed of a copolymer of atleast one of the following acids and at least one of the followingglycols. The acids include terephthalic acid, isophthalic acid, phthalicanhydride, oxalic acid, malonic acid, succinic acid, pentanedioic acid,hexanedioic acid, octanedioic acid, nonanedioic acid, adipic acid,azelaic acid, sebacic acid, dodecanedioic acid, dimer acid (a mixture),ρ-hydroxybenzoate, trimellitic anhydride, ε-caprolactone, andβ-methyl-δ-valerolactone. The glycols includes ethylene glycol,propylene glycol, butylene glycol, pentylene glycol, 1,4-butanediol,1,5-pentanediol, 1,6-hexanediol, neopentylene glycol, polyethyleneglycol, polytetramethylene glycol, 1,4-cyclohexane dimethanol,pentaerythritol, and 3-methyl-1,5-pentanediol.

Polyether polyols are prepared by the ring-opening additionpolymerization of an alkylene oxide (e.g. ethylene oxide and propyleneoxide) with an initiator of a polyhydric alcohol (e.g. diethyleneglycol), which is an active hydride. Specifically, polypropylene glycol(PPG), polyethylene glycol (PEG) or propylene oxide-ethylene oxidecopolymer can be obtained. Polytetramethylene ether glycol (PTMG) isprepared by the ring-opening polymerization of tetrahydrofuran, producedby dehydration of 1,4-butanediol or hydrogenation of furan.Tetrahydrofuran can form a copolymer with alkylene oxide. Specifically,tetrahydrofuran-propylene oxide copolymer or tetrahydrofuran-ethyleneoxide copolymer can be formed. The polyether polyol may be used eitheralone or in a combination.

Polycarbonate polyol is obtained by the condensation of a known polyol(polyhydric alcohol) with phosgene, chloroformic acid ester, dialkylcarbonate or diallyl carbonate. Particularly preferred polycarbonatepolyol contains a polyol component using 1,6-hexanediol. 1,4-butanediol,1,3-butanediol, neopentylglycol or 1,5-pentanediol. Polycarbonatepolyols can be used either alone or in a combination with other polyols.

Polybutadiene polyol includes liquid diene polymer containing hydroxylgroups having an average of at least 1.7 functional groups, and may becomposed of diene polymer or diene copolymer having 4 to 12 carbonatoms, or a copolymer of such diene with addition to polymerizableα-olefin monomer having 2 to 2.2 carbon atoms. Specific examples includebutadiene homopolymer, isoprene homopolymer, butadiene-styrenecopolymer, butadiene-isoprene copolymer, butadiene-acrylonitrilecopolymer, butadiene-2-ethyl hexyl acrylate copolymer, andbutadiene-n-octadecyl acrylate copolymer. These liquid diene polymerscan be obtained, for example, by heating a conjugated diene monomer inthe presence of hydrogen peroxide in a liquid reactant.

Isocyanates suitable for use in the UV-curable compositions include:trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylenediisocyanate, hexamethylene diisocyanate, ethylene diisocyanate,diethylidene diisocyanate, propylene diisocyanate, butylenesdiisocyanate, bitolylene diisocyanate, tolidine isocyanate, isophoronediisocyanate, dimeryl diisocyanate, dodecane-1,12-diisocyanate,1,10-decamethylene diisocyanate, cyclohexylene-1,2-diisocyanate,1,10-decamethylene diisocyanate, 1-chlorobenzene-2,4-diisocyanate,furfurylidene diisocyanate, 2,4,4-trimethyl hexamethylene diisocyanate,2,2,4-trimethyl hexamethylene diisocyanate, dodecamethylenediisocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexanediisocyanate, 1,3-cyclobutane diisocyanate, 1,4-cyclohexanediisocyanate, 4,4′-methylenebis(cyclohexyl isocyanate),4,4′-methylenebis(phenyl isocyanate), 1-methyl-2,4-cyclohexanediisocyanate, 1-methyl-2,6-cyclohexane diisocyanate, 1,3-bis(isocyanato-methyl)cyclohexane,1,6-diisocyanato-2,2,4,4-tetra-methylhexane,1,6-diisocyanato-2,4,4-tetra-trimethylhexane,trans-cyclohexane-1,4-diisocyanate,3-isocyanato-methyl-3,5,5-trimethylcyclo-hexyl isocyanate,1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, cyclo-hexylisocyanate, dicyclohexylmethane 4,4′-diisocyanate,1,4-bis(isocyanatomethyl) cyclohexane, m-phenylene diisocyanate,m-xylylene diisocyanate, m-tetramethylxylylene diisocyanate, p-phenylenediisocyanate, p,p′-biphenyl diisocyanate, 3,3′-dimethyl-4,4′-biphenylenediisocyanate, 3,3′-dimethoxy-4,4′-biphenylene diisocyanate,3,3′-diphenyl-4,4′-biphenylene diisocyanate, 4,4′-biphenylenediisocyanate, 3,3′-dichloro-4,4′-biphenylene diisocyanate,1,5-naphthalene diisocyanate, 4-chloro-1,3-phenylene diisocyanate,1,5-tetrahydronaphthalene diisocyanate, metaxylene diisocyanate,2,4-toluene diisocyanate, 2,4′-diphenylmethane diisocyanate,2,4-chlorophenylene diisocyanate, 4,4′-diphenylmethane diisocyanate,p,p′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate,2,6-tolylene diisocyanate, 2,2-diphenylpropane-4,4′-diisocyanate,4,4′-toluidine diisocyanate, dianidine diisocyanate, 4,4′-diphenyl etherdiisocyanate, 1,3-xylylene diisocyanate, 1,4-naphthylene diisocyanate,azobenzene-4,4′-diisocyanate, diphenyl sulfone-4,4′-diisocyanate,triphenylmethane 4,4,4″-triisocyanate, isocyanatoethyl methacrylate,3-isopropenyl-α,α-dimethylbenzyl-isocyanate, dichlorohexamethylenediisocyanate, ω,ω′-diisocyanato-1,4-diethylbenzene, polymethylenepolyphenylene polyisocyanate, isocyanurate modified compounds, andcarbodiimide modified compounds, as well as biuret modified compounds ofthe above polyisocyanates. These isocyanates may be used either alone orin combination. These combination isocyanates include triisocyanates,such as biuret of hexamethylene diisocyanate and triphenylmethanetriisocyanates, and polyisocyanates, such as polymeric diphenylmethanediisocyanate.

The UV-curable compositions also can incorporate optional chainextenders. Non-limiting examples of these extenders include polyols,polyamine compounds, and mixtures of these. Polyol extenders may beprimary, secondary, or tertiary polyols. Specific examples of monomersof these polyols include: trimethylolpropane (TMP), ethylene glycol,1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol,propylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol,2,3-butanediol, 1,2-pentanediol, 2,3-pentanediol, 2,5-hexanediol,2,4-hexanediol, 2-ethyl-1,3-hexanediol, cyclohexanediol, and2-ethyl-2-(hydroxymethyl)-1,3-propanediol. Diamines also can be added tourethane prepolymer to function as chain extenders. Suitable diaminesinclude: tetramethylenediamine, pentamethylenediamine,hexamethylenediamine, p,p′-methylenedianiline, p-phenylenediamine andothers. Aromatic diamines have a tendency to provide a stiffer (i.e.,having a higher Mooney viscosity) product than aliphatic orcycloaliphatic diamines. Suitable polyamines that can be used as chainextenders include primary, secondary, and tertiary amines, such asdiamine, triamine and tetramine. Examples of these include: an aliphaticamine, such as hexamethylenediamine; an alicyclic amine, such as3,3′-dimethyl-4,4′-diaminodicyclohexyl methane; or, an aromatic amine,such as 4,4′-methylene bis-2-chloroaniline,2,2′,3,3′-tetrachloro-4,4′-diaminophenyl methane or4,4′-diaminodiphenyl; and 2,4,6-tris(dimethylaminomethyl) phenol. Thesechain extenders can be used either alone or in combination.

The UV-curable compositions also may include plasticizers. Examples ofsuitable plasticizers include: dioctyl phthalate (DOP), dibutylphthalate (DBP), dioctyl adipate (DOA), triethylene glycol dibenzoate,tricresyl phosphate, dioctyl phthalate, aliphatic ester ofpentaerythritol, dioctyl sebacate, and diisooctyl azelate. In additionto the material discussed above, the UV-curable compositions canincorporate one or more polymers in addition to the thermoplasticurethane and crosslinking agent. These additional polymers may be addedas need for a desired effect, such as softening an otherwise overly hardcover composition. Examples of suitable additional polymers for use inthe present invention include, but are not limited to, the following:thermoplastic elastomer, thermoset elastomer, synthetic rubber,thermoplastic vulcanizate, copolymeric ionomer, terpolymeric ionomer,polycarbonate, polyolefin, polyamide, copolymeric polyamide, polyesters,polyvinyl alcohols, acrylonitrile-butadiene-styrene copolymers,polyarylate, polyacrylate, polyphenyl ether, modified-polyphenyl ether,high-impact polystyrene, diallyl phthalate polymer, metallocenecatalyzed polymers, acrylonitrile-styrene-butadiene (ABS),styrene-acrylonitrile (SAN) (including olefin-modified SAN andacrylonitrile styrene acrylonitrile), styrene-maleic anhydride (S/MA)polymer, styrenic copolymer, functionalized styrenic copolymer,functionalized styrenic terpolymer, styrenic terpolymer, cellulosepolymer, liquid crystal polymer (LCP), ethylene-propylene-dieneterpolymer (EPDM), ethylene-vinyl acetate copolymers (EVA),ethylene-propylene copolymer, ethylene vinyl acetate, polyurea, andpolysiloxane or any metallocene-catalyzed polymers of these species.Particularly suitable plasticizers for use in the compositions withinthe scope of the present invention include: polyethylene-terephthalate,polybutyleneterephthalate, polytrimethylene-terephthalate,ethylene-carbon monoxide copolymer, polyvinyl-diene fluorides,polyphenylenesulfide, polypropylene-oxide, polyphenyloxide,polypropylene, functionalized polypropylene, polyethylene,ethylene-octene copolymer, ethylene-methyl acrylate, ethylene-butylacrylate, polycarbonate, polysiloxane, functionalized polysiloxane,copolymeric ionomer, terpolymeric ionomer, polyetherester elastomer,polyesterester elastomer, polyetheramide elastomer, propylene-butadienecopolymer, modified copolymer of ethylene and propylene, styreniccopolymer (including styrenic block copolymer and randomly distributedstyrenic copolymer, such as styrene-isobutylene copolymer andstyrene-butadiene copolymer), partially or fully hydrogenatedstyrene-butadiene-styrene block copolymers such asstyrene-(ethylene-propylene)-styrene orstyrene-(ethylene-butylene)-styrene block copolymers, partially or fullyhydrogenated styrene-butadiene-styrene block copolymers with functionalgroup, polymers based on ethylene-propylene-(diene), polymers based onfunctionalized ethylene-propylene-(diene), dynamically vulcanizedpolypropylene/ethylene-propylene-diene-copolymer, thermoplasticvulcanizates based on ethylene-propylene-(diene), natural rubber,styrene-butadiene rubber, nitrile rubber, chloroprene rubber,fluorocarbon rubber, butyl rubber, acrylic rubber, silicone rubber,chlorosulfonated polyethylene, polyisobutylene, alfin rubber, polyesterrubber, epichlorphydrin rubber, chlorinated isobutylene-isoprene rubber,nitrile-isobutylene rubber, 1,2-polybutadiene, 1,4-polybutadiene,cis-polyisoprene, trans-polyisoprene, and polybutylene-octene.

Suitable polyamides for use as an additional material in thecompositions also include resins obtained by: (1) polycondensation of(a) a dicarboxylic acid, such as oxalic acid, adipic acid, sebacic acid,terephthalic acid, isophthalic acid or 1,4-cyclohexylidicarboxylic acid,with (b) a diamine, such as ethylenediamine, tetramethylenediamine,pentamethylenediamine, hexamethylene-diamine or decamethylenediamine,1,4-cyclohexyldiamine or m-xylylenediamine; (2) a ring-openingpolymerization of cyclic lactam, such as ε-caprolactam or ω-laurolactam;(3) polycondensation of an aminocarboxylic acid, such as 6-amino caproicacid, 9-aminononaoic acid, 11-aminoudecanoic acid or 12-aminododecanoicacid; or, (4) copolymerization of a cyclic lactam with a dicarboxylicacid and a diamine. Specific examples of suitable polyamides includeNylon 6, Nylon 66, Nylon 610, Nylon 11, Nylon 12, copolymerized Nylon,Nylon MXD6, and Nylon 46. Other preferred materials suitable for use asan additional material in compositions within the scope of the presentinvention include polyester elastomers marketed under the name SKYPEL bySK Chemicals of South Korea, or triblock copolymers marketed under thename HG-252 by Kuraray Corporation of Kurashiki, Japan. These triblockcopolymers have at least one polymer block comprising an aromatic vinylcompound and at least one polymer block comprising a conjugated dienecompound, and a hydroxyl group at a block copolymer. The materialslisted above all can provide for particular enhancements to ball layers.

Ionomeric polymers often are found in covers and intermediate layers ofgolf balls. These ionomers also are well suited for blending intocompositions disclosed herein. Suitable ionomeric polymers (i.e.,copolymer- or terpolymer-type ionomers) include α-olefin/unsaturatedcarboxylic acid copolymer-type ionomeric or terpolymer-type ionomericresins that can be described as copolymer E/X/Y, where E representsethylene, X represents a softening comonomer such as acrylate ormethacrylate, and Y is acrylic or methacrylic acid. The acid moiety of Yis neutralized to form an ionomer by a cation such as lithium, sodium,potassium, magnesium, calcium, barium, lead, tin, zinc or aluminum.Also, a combination of such cations is used for the neutralization.Copolymeric ionomers are obtained by neutralizing at least portion ofcarboxylic groups in a copolymer of an α-olefin and an α,β-unsaturatedcarboxylic acid having 3 to 8 carbon atoms, with a metal ion. Examplesof suitable α-olefins include ethylene, propylene, 1-butene, and1-hexene. Examples of suitable unsaturated carboxylic acids includeacrylic, methacrylic, ethacrylic, alphachloroacrylic, crotonic, maleic,fumaric, and itaconic acid. Copolymeric ionomers include ionomers havingvaried acid contents and degrees of acid neutralization, neutralized bymonovalent or bivalent cations discussed above.

Terpolymeric ionomers are obtained by neutralizing at least portion ofcarboxylic groups in a terpolymer of an α-olefin, and an α,β-unsaturatedcarboxylic acid having 3 to 8 carbon atoms and an α,β-unsaturatedcarboxylate having 2 to 22 carbon atoms with metal ion. Examples ofsuitable α-olefins include ethylene, propylene, 1-butene, and 1-hexene.Examples of suitable unsaturated carboxylic acids include acrylic,methacrylic, ethacrylic, alphachloroacrylic, crotonic, maleic, fumaric,and itaconic acid. Terpolymeric ionomers include ionomers having variedacid contents and degrees of acid neutralization, neutralized bymonovalent or bivalent cations discussed above. Examples of suitableionomeric resins include those marketed under the name SURLYNmanufactured by E.I. DuPont de Nemours & Company of Wilmington, Del.,and IOTEK manufactured by Exxon Mobil Corporation of Irving, Tex.

Silicone materials also are well suited for blending into compositionsdisclosed herein. These can be monomers, oligomers, prepolymers, orpolymers, with or without additional reinforcing filler. One type ofsilicone material that is suitable can incorporate at least 1 alkenylgroup having at least 2 carbon atoms in their molecules. Examples ofthese alkenyl groups include, but are not limited to, vinyl, allyl,butenyl, pentenyl, hexenyl and decenyl. The alkenyl functionality can belocated at any location of the silicone structure, including one or bothterminals of the structure. The remaining (i.e., non-alkenyl)silicon-bonded organic groups in this component are independentlyselected from hydrocarbon or halogenated hydrocarbon groups that containno aliphatic unsaturation. Non-limiting examples of these include: alkylgroups, such as methyl, ethyl, propyl, butyl, pentyl and hexyl;cycloalkyl groups, such as cyclohexyl and cycloheptyl; aryl groups suchas phenyl, tolyl and xylyl; aralkyl groups, such as benzyl andphenethyl; and halogenated alkyl groups, such as 3,3,3-trifluoropropyland chloromethyl. Another type of silicone material suitable for use inthe present invention is one having hydrocarbon groups that lackaliphatic unsaturation. Specific examples of suitable silicones for usein making compositions of the present invention include the following:trimethylsiloxy-endblocked dimethylsiloxane-methylhexenylsiloxanecopolymers, dimethylhexenlylsiloxy-endblockeddimethylsiloxane-methylhexenylsiloxane copolymers;trimethylsiloxy-endblocked dimethylsiloxane-methylvinylsiloxanecopolymers; trimethylsiloxy-endblockedmethylphenylsiloxane-dimethylsiloxane-methylvinylsiloxane copolymers;dimethylvinylsiloxy-endblocked dimethylpolysiloxanes;dimethylvinylsiloxy-endblocked dimethylsiloxane-methylvinylsiloxanecopolymers; dimethylvinylsiloxy-endblocked methylphenylpolysiloxanes;dimethylvinylsiloxy-endblockedmethylphenylsiloxane-dimethylsiloxane-methylvinylsiloxane copolymers;and, the copolymers listed above, in which at least one end group isdimethylhydroxysiloxy. Commercially available silicones suitable includeSilastic by Dow Corning Corp. of Midland, Mich., Blensil by GE Siliconesof Waterford, N.Y., and Elastosil by Wacker Silicones of Adrian. Mich.

Other types of copolymers also may be added to compositions disclosedherein. Examples of copolymers comprising epoxy monomers and which aresuitable for use include styrene-butadiene-styrene block copolymers, inwhich the polybutadiene block contains epoxy group, andstyrene-isoprene-styrene block copolymers, in which the polyisopreneblock contains epoxy. Commercially available examples of these epoxyfunctional copolymers include ESBS A1005, ESBS A1010. ESBS A1020, ESBSAT018, and ESBS AT019, marketed by Daicel Chemical Industries, Ltd.

UV-curable polyurethane-containing compositions disclosed herein alsocan include, in suitable amounts, one or more additional ingredientsgenerally employed in golf balls and ball compositions. Agents providedto achieve specific functions, such as additives and stabilizers, can bepresent. Suitable ingredients include colorants, UV stabilizers,photostabilizers, antioxidants, colorants, dispersants, mold releasingagents, processing aids, and fillers. The compositions can incorporate,for example, inorganic fillers, such as titanium dioxide, calciumcarbonate, zinc sulfide or zinc oxide. Additional fillers can be chosento impart additional density to the compositions, such as zinc oxide,barium sulfate, tungsten or any other metallic powder having densityhigher than that of the base polymeric resin. Any organic or inorganicfibers, either continuous or non-continuous, also can be in thecompositions. An example of these is silica-reinforcing filler. Thisfiller preferably is selected from finely divided, heat-stable minerals,such as fumed and precipitated forms of silica, silica aerogels andtitanium dioxide having a specific surface area of at least about 10m²/gram.

The various possible components of the compositions disclosed herein canbe mixed together, with or without melting them. Dry blending equipment,such as a tumbler mixer. V-blender, or ribbon blender, can be used toprepare the composition. Materials can be added to the composition usinga mill, internal mixer, extruder or combinations of these, with orwithout application of thermal energy to produce melting. The additionalmaterials also can be added to a color concentrate, which then is addedto the composition to impart a white color to golf ball.

Methods for UV curing include:

1. Exposed to UV light during injection molding process

2. Exposed to UV light after injection molding process

3. Half cup injection molding, compression molding, and then UVirradiation

4. Half cup injection molding and UV irradiation during compressionmolding process

A preferred method involves injection molding a core, intermediatelayer, or cover of the UV-curable polyurethane-containing compositioninto a mold without inducing heavy crosslinking. The product from thisprocess then is compression-molded and subjected to UV irradiation toinduce partial or full crosslinking. In another preferred method,injection molding is used to inject the composition around a corepositioned in a mold, in which UV irradiation is applied to inducecrosslinking. In yet another preferred method, an intermediate layer ora cover of the composition can be prepared by injection moldinghalf-shells. The half shells are then positioned around a core andcompression molded and subjected to UV irradiation. The heat andpressure first melt the composition to seal the two half shells togetherto form a complete layer. UV irradiation energy induces crosslinking ofthe thermoplastic urethane.

In addition to the above, when used to form a cover layer, a preferredembodiment of the method involves preparing the cover layer usinginjection molding and forming dimples on the surface of the cover layer,while inducing full or partial crosslinking of the layer duringinjection molding. Alternately, the cover layer can be formed usinginjection molding without dimples, after which the cover layer iscompression molded to form dimples and also induce full or partialcrosslinking.

In several embodiments, the UV-curable polyurethane constitutes themajority component of an intermediate layer and/or cover layer. Inparticular, the UV-curable polyurethane, constitutes greater than 30weight %, more preferably greater than 40 weight %, and most preferablygreater than 50 weight %, of the total weight of the materials formingthe intermediate and/or cover layer.

Additional Polymer Components

Additional polymers may also be used as a separate component of thecore, cover layer or intermediate layer of the golf balls. Theseadditional polymers may include, without limitation, other synthetic andnatural rubbers, including the polyalkenamers, cis-1,4-polybutadiene,trans-1,4-polybutadiene, 1,2-polybutadiene, cis-polyisoprene,trans-polyisoprene, polychloroprene, polybutylene, styrene-butadienerubber, styrene-butadiene-styrene block copolymer and partially andfully hydrogenated equivalents, styrene-isoprene-styrene block copolymerand partially and fully hydrogenated equivalents, nitrile rubber,silicone rubber, and polyurethane, as well as mixtures of these,carboxyl-terminated butadiene (CTBN) and butadiene grafted with maleicanhydride (BMA), thermoset polymers such as thermoset polyurethanes andthermoset polyureas, as well as thermoplastic polymers includingthermoplastic elastomers such as unimodal ethylene/carboxylic acidcopolymers, unimodal ethylene/carboxylic acid/carboxylate terpolymers,bimodal ethylene/carboxylic acid copolymers, bimodal ethylene/carboxylicacid/carboxylate terpolymers, unimodal ionomers, bimodal ionomers,modified unimodal ionomers, modified bimodal ionomers, thermoplasticpolyurethanes, thermoplastic polyureas, polyesters, copolyesters,polyamides, copolyamides, polycarbonates, polyolefins, polyphenyleneoxide, polyphenylene sulfide, diallyl phthalate polymer, polyimides,polyvinyl chloride, polyamide-ionomer, polyurethane-ionomer, polyvinylalcohol, polyarylate, polyacrylate, polyphenylene ether, impact-modifiedpolyphenylene ether, polystyrene, high impact polystyrene,acrylonitrile-butadiene-styrene copolymer styrene-acrylonitrile (SAN),acrylonitrile-styrene-acrylonitrile, styrene-maleic anhydride (S/MA)polymer, styrenic copolymer, functionalized styrenic copolymer,functionalized styrenic terpolymer, styrenic terpolymer, cellulosepolymer, liquid crystal polymer (LCP), ethylene-propylene-dieneterpolymer (EPDM), ethylene-vinyl acetate copolymers (EVA),ethylene-propylene copolymer, ethylene vinyl acetate, polyurea, andpolysiloxane and any and all combinations thereof.

The olefinic thermoplastic elastomers include metallocene-catalyzedpolyolefins, ethylene-octene copolymer, ethylene-butene copolymer, andethylene-propylene copolymers all with or without controlled tacticityas well as blends of polyolefins having ethyl-propylene-non-conjugateddiene terpolymer, rubber-based copolymer, and dynamically vulcanizedrubber-based copolymer. Examples of these include products sold underthe trade names SANTOPRENE, DYTRON, VISAFLEX, and VYRAM by AdvancedElastomeric Systems of Houston, Tex., and SARLINK by DSM of Haarlen, theNetherlands.

Examples of rubber-based thermoplastic elastomers include multiblockrubber-based copolymers, particularly those in which the rubber blockcomponent is based on butadiene, isoprene, or ethylene/butylene. Thenon-rubber repeating units of the copolymer may be derived from anysuitable monomers, including meth(acrylate) esters, such as methylmethacrylate and cyclohexylmethacrylate, and vinyl arylenes, such asstyrene. Examples of styrenic copolymers are resins manufactured byKraton Polymers (formerly of Shell Chemicals) under the trade namesKRATON D (for styrene-butadiene-styrene and styrene-isoprene-styrenetypes) and KRATON G (for styrene-ethylene-butylene-styrene andstyrene-ethylene-propylene-styrene types) and Kuraray under the tradename SEPTON. Examples of randomly distributed styrenic polymers includeparamethylstyrene-isobutylene (isobutene) copolymers developed byExxonMobil Chemical Corporation and styrene-butadiene random copolymersdeveloped by Chevron Phillips Chemical Corp.

Further polymers include copolyester thermoplastic elastomers whichinclude polyether ester block copolymers, polylactone ester blockcopolymers, and aliphatic and aromatic dicarboxylic acid copolymerizedpolyesters. Polyether ester block copolymers are copolymers comprisingpolyester hard segments polymerized from a dicarboxylic acid and a lowmolecular weight diol, and polyether soft segments polymerized from analkylene glycol having 2 to 10 atoms. Polylactone ester block copolymersare copolymers having polylactone chains instead of polyether as thesoft segments discussed above for polyether ester block copolymers.Aliphatic and aromatic dicarboxylic copolymerized polyesters arecopolymers of an acid component selected from aromatic dicarboxylicacids, such as terephthalic acid and isophthalic acid, and aliphaticacids having 2 to 10 carbon atoms with at least one diol component,selected from aliphatic and alicyclic diols having 2 to 10 carbon atoms.Blends of aromatic polyester and aliphatic polyester also may be usedfor these. Examples of these include products marketed under the tradenames HYTREL by E.I. DuPont de Nemours & Company, and SKYPEL by S.K.Chemicals of Seoul, South Korea.

Examples of other thermoplastic elastomers suitable as additionalpolymer components include those having functional groups, such ascarboxylic acid, maleic anhydride, glycidyl, norbornene, and hydroxylfunctionalities. An example of these includes a block polymer having atleast one polymer block A comprising an aromatic vinyl compound and atleast one polymer block B comprising a conjugated diene compound, andhaving a hydroxyl group at the terminal block copolymer, or itshydrogenated product. An example of this polymer is sold under the tradename SEPTON HG-252 by Kuraray Company of Kurashiki, Japan. Otherexamples of these include: maleic anhydride functionalized triblockcopolymer consisting of polystyrene end blocks andpoly(ethylene/butylene), sold under the trade name KRATON FG 1901X byShell Chemical Company; maleic anhydride modified ethylene-vinyl acetatecopolymer, sold under the trade name FUSABOND by E.I. DuPont de Nemours& Company; ethylene-isobutyl acrylate-methacrylic acid terpolymer, soldunder the trade name NUCREL by E.I. DuPont de Nemours & Company;ethylene-ethyl acrylate-methacrylic anhydride terpolymer, sold under thetrade name BONDINE AX 8390 and 8060 by Sumitomo Chemical Industries;brominated styrene-isobutylene copolymers sold under the trade nameBROMO XP-50 by Exxon Mobil Corporation; and resins having glycidyl ormaleic anhydride functional groups sold under the trade name LOTADER byElf Atochem of Puteaux, France.

The other polymer materials may also include the polyamides. The term“polyamide” as used herein includes both homopolyamides andcopolyamides. Illustrative polyamides for use in thepolyalkenamer/polyamide compositions include those obtained by: (1)polycondensation of (a) a dicarboxylic acid, such as oxalic acid, adipicacid, sebacic acid, terephthalic acid, isophthalic acid, or1,4-cyclohexanedicarboxylic acid, with (b) a diamine, such asethylenediamine, tetramethylenediamine, pentamethylenediamine,hexamethylenediamine, decamethylenediamine, 1,4-cyclohexyldiamine orm-xylylenediamine; (2) a ring-opening polymerization of cyclic lactam,such as ε-caprolactam or ω-laurolactam; (3) polycondensation of anaminocarboxylic acid, such as 6-aminocaproic acid, 9-aminononanoic acid,11-aminoundecanoic acid or 12-aminododecanoic acid; (4) copolymerizationof a cyclic lactam with a dicarboxylic acid and a diamine; or anycombination of (1)-(4). In certain examples, the dicarboxylic acid maybe an aromatic dicarboxylic acid or a cycloaliphatic dicarboxylic acid.In certain examples, the diamine may be an aromatic diamine or acycloaliphatic diamine. Specific examples of suitable polyamides includepolyamide 6; polyamide 11; polyamide 12; polyamide 4,6; polyamide 6,6;polyamide 6,9; polyamide 6,10; polyamide 6,12; polyamide MXD6; PA12, CX;PA12, IT; PPA; PA6, IT; and PA6/PPE. Also included are the crosslinkedpolyamide compositions descried in copending application 61/746,540filed on 27 Dec. 2012 in the name of the Taylor Made Golf Co. Inc andincorporated herein by reference in its entirety.

The polyamide (which may a polyamide as described above) may also beblended with a functional polymer modifier of. The functional polymermodifier of the polyamide can include copolymers or terpolymers having aglycidyl group, hydroxyl group, maleic anhydride group or carboxylicgroup, collectively referred to as functionalized polymers. Thesecopolymers and terpolymers may comprise an α-olefin. Examples ofsuitable α-olefins include ethylene, propylene, 1-butene, 1-pentene,3-methyl-1-butene, 1-hexene, 4-methyl-1-petene, 3-methyl-1-pentene,1-octene, 1-decene-, 1-dodecene, 1-tetradecene, 1-hexadecene,1-octadecene, 1-eicocene, 1-dococene, 1-tetracocene, 1-hexacocene,1-octacocene, and 1-triacontene. One or more of these α-olefins may beused.

Examples of suitable glycidyl groups in copolymers or terpolymers in thepolymeric modifier include esters and ethers of aliphatic glycidyl, suchas allylglycidylether, vinylglycidylether, glycidyl maleate anditaconatem glycidyl acrylate and methacrylate, and also alicyclicglycidyl esters and ethers, such as 2-cyclohexene-1-glycidylether,cyclohexene-4,5 diglyxidylcarboxylate, cyclohexene-4-glycidylcarboxylate, 5-norboenene-2-methyl-2-glycidyl carboxylate, andendocis-bicyclo(2,2,1)-5-heptene-2,3-diglycidyl dicarboxylate. Thesepolymers having a glycidyl group may comprise other monomers, such asesters of unsaturated carboxylic acid, for example, alkyl(meth)acrylatesor vinyl esters of unsaturated carboxylic acids. Polymers having aglycidyl group can be obtained by copolymerization or graftpolymerization with homopolymers or copolymers.

Examples of suitable terpolymers having a glycidyl group include LOTADERAX8900 and AX8920, marketed by Atofina Chemicals, ELVALOY marketed byE.I. Du Pont de Nemours & Co., and REXPEARL marketed by NipponPetrochemicals Co., Ltd. Additional examples of copolymers comprisingepoxy monomers and which are suitable for use within the scope of thepresent invention include styrene-butadiene-styrene block copolymers inwhich the polybutadiene block contains epoxy group, andstyrene-isoprene-styrene block copolymers in which the polyisopreneblock contains epoxy. Commercially available examples of these epoxyfunctional copolymers include ESBS A1005, ESBS A1010, ESBS A1020, ESBSAT018, and ESBS AT019, marketed by Daicel Chemical Industries, Ltd.

Examples of polymers or terpolymers incorporating a maleic anhydridegroup suitable include maleic anhydride-modified ethylene-propylenecopolymers, maleic anhydride-modified ethylene-propylene-dieneterpolymers, maleic anhydride-modified polyethylenes, maleicanhydride-modified polypropylenes, ethylene-ethylacrylate-maleicanhydride terpolymers, and maleic anhydride-indene-styrene-cumaronepolymers. Examples of commercially available copolymers incorporatingmaleic anhydride include: BONDINE, marketed by Sumitomo Chemical Co.,such as BONDINE AX8390, an ethylene-ethyl acrylate-maleic anhydrideterpolymer having a combined ethylene acrylate and maleic anhydridecontent of 32% by weight, and BONDINE TX TX8030, an ethylene-ethylacrylate-maleic anhydride terpolymer having a combined ethylene acrylateand maleic anhydride content of 15% by weight and a maleic anhydridecontent of 1% to 4% by weight; maleic anhydride-containing LOTADER 3200,3210, 6200, 8200, 3300, 3400, 3410, 7500, 5500, 4720, and 4700, marketedby Atofina Chemicals; EXXELOR VA1803, a maleic anhydride-modifiedethylene-propylene copolymer having a maleic anhydride content of 0.7%by weight, marketed by Exxon Chemical Co.; and KRATON FG 1901X, a maleicanhydride functionalized triblock copolymer having polystyrene endblocksand poly(ethylene/butylene) midblocks, marketed by Shell Chemical.

Preferably the functional polymer component is a maleic anhydridegrafted polymer, preferably a maleic anhydride grafted polyolefin (forexample, Exxellor VA 1803). Styrenic block copolymers are copolymers ofstyrene with butadiene, isoprene, or a mixture of the two. Additionalunsaturated monomers may be added to the structure of the styrenic blockcopolymer as needed for property modification of the resultingSBC/urethane copolymer. The styrenic block copolymer can be a diblock ora triblock styrenic polymer. Examples of such styrenic block copolymersare described in, for example, U.S. Pat. No. 5,436,295 to Nishikawa etal. The styrenic block copolymer can have any known molecular weight forsuch polymers, and it can possess a linear, branched, star, dendrimericor combination molecular structure. The styrenic block copolymer can beunmodified by functional groups, or it can be modified by hydroxylgroup, carboxyl group, or other functional groups, either in its chainstructure or at one or more terminus. The styrenic block copolymer canbe obtained using any common process for manufacture of such polymers.The styrenic block copolymers also may be hydrogenated using well-knownmethods to obtain a partially or fully saturated diene monomer block.

Other materials suitable for use as additional polymers in the presentlydisclosed golf balls include polyester thermoplastic elastomers marketedunder the tradename SKYPEL™ by SK Chemicals of South Korea, or diblockor triblock copolymers marketed under the tradename SEPTON™ by KurarayCorporation of Kurashiki, Japan, and KRATON™ by Kraton Polymers Group ofCompanies of Chester, United Kingdom. For example, SEPTON HG 252 is atriblock copolymer, which has polystyrene end blocks and a hydrogenatedpolyisoprene midblock and has hydroxyl groups at the end of thepolystyrene blocks. HG-252 is commercially available from KurarayAmerica Inc. (Houston, Tex.).

A further example of a material suitable for use as additional polymersin the presently disclosed golf balls is a specialty propylene elastomeras described, for example, in US 2007/0238552 A1, and incorporatedherein by reference in its entirety. A specialty propylene elastomerincludes a thermoplastic propylene-ethylene copolymer composed of amajority amount of propylene and a minority amount of ethylene. Thesecopolymers have at least partial crystallinity due to adjacent isotacticpropylene units. Although not bound by any theory, it is believed thatthe crystalline segments are physical crosslinking sites at roomtemperature, and at high temperature (i.e., about the melting point),the physical crosslinking is removed and the copolymer is easy toprocess. According to one embodiment, a specialty propylene elastomerincludes at least about 50 mole % propylene co-monomer. Specialtypropylene elastomers can also include functional groups such as maleicanhydride, glycidyl, hydroxyl, and/or carboxylic acid. Suitablespecialty propylene elastomers include propylene-ethylene copolymersproduced in the presence of a metallocene catalyst. More specificexamples of specialty propylene elastomers are illustrated below.Specialty propylene elastomers are commercially available under thetradename VISTAMAXX from ExxonMobil Chemical.

An especially preferred component suitable for use as an additionalpolymer in the presently disclosed golf balls include thepolyalkenamers. The term “polyalkenamer” is used interchangeably hereinwith the term “polyalkenamer rubber” and means a rubbery polymer of oneor more cycloalkenes having from 4-20, ring carbon atoms. Thepolyalkenamers may be prepared by ring opening metathesis polymerizationof one or more cycloalkenes in the presence of organometallic catalystsas described in U.S. Pat. Nos. 3,492,245, and 3,804,803, the entirecontents of both of which are herein incorporated by reference.

Another component for use as an additional polymer in the presentlydisclosed golf balls include the carboxylated elastomers described incopending application Ser. No. 13/719,060 filed on Dec. 18, 2012 in thename of Taylor Made Golf Co., the entire contents of which are hereinincorporated by reference. The term carboxylated elastomer (CE)composition as used herein is intended to mean the family of polymerswhich are long chain elastomeric rubbers containing pendant carboxylgroups at random various points along the chain as may be graphicallyillustrated below:

The carboxylated elastomer comprises an elastomer backbone and carboxypendant groups, wherein R may be a hydrogen, a metal (for example, analkali metal, an alkaline earth metal, or a transition metal), anammonium or a quaternary ammonium group, an acyl group (for exampleacetyl (CH₃C(O)) group), an alkyl group (such as an ester), an acidanhydride group, and combinations thereof; and R₁ may be a hydrogen, analkyl, or an aryl group. Although the pendant carboxy groups aredepicted as being in interior positions along the elastomer backbone,the carboxylated elastomer may also include terminal carboxy groupsoccurring at one or more chain ends.One method of introducing the carboxy groups is by copolymerization of asuitable olefin monomer with a monomer comprising a carboxy group. Thefirst preparation of a carboxylic elastomer was recorded in 1933 andinvolved the copolymerization of butadiene and acrylic acid. Examples ofsuitable olefin monomers, include, but are not limited to, styrene,vinyltoluene, alpha-methylstyrene, butadiene, isoprene, hexadiene,dichlorovinylidene, vinylchloride, ethylene, propylene, butylene, andisobutylene. Examples of suitable monomers comprising a carboxy groupinclude, but are not limited to, acrylic acid, alkyacrylate, alkylalkacrylates, maleic anhydride, maleimide, acrylamide and2-acrylamido-2-methyl-1-propane sulfonic acid.A class of carboxylated elastomers for use in this invention are thecarboxylated nitrile rubbers which may be any of those known in the art.These are copolymers of butadiene, acrylonitrile and one or moreα,μ-unsaturated carboxylic acids and which have nitrile rubber as theelastomer backbone. A diagram of the backbone is shown below.

The carboxylic acids which are pendant to the above backbone may containone or more carboxylic groups. Because of cost and availability, it ispreferred that the carboxylic acids be selected from acrylic,methacrylic, fumaric, maleic and itaconic acids. The copolymers may beprepared by the well known emulsion free radical process. Theacrylonitrile content of the copolymer may be from about 20 to about 40percent by weight of the copolymer. The total content of carboxylic acidin the copolymer may be from about 0.5 to about 10 percent by weight ofthe copolymer. Butadiene forms the balance to 100 percent by weight ofthe copolymer. The viscosity of the copolymer is generally within theMooney range (ML 1+4 at 100° C.) of from about 40 to about 80. U.S. Pat.Nos. 4,271,052 and 4,525,517 disclose carboxylated nitrile rubbers foruse in this invention and such disclosures are incorporated herein byreference. There are a number of carboxylated elastomers that arecommercially available from Noveon under the tradename HYCAR includingHYCAR CTBN 1300X8 and CTBN 1300X8F which are a carboxyl terminatedbutadiene-acrylonitrile copolymers. HYCAR VTBNX 1300X33 which is amethacrylate terminated butadiene-acrylonitrile copolymer and HYCAR ATBN1300X16 is an amine terminated butadiene-acrylonitrile.

Another method for introducing the carboxy groups into the particularelastomer backbone is by grafting carboxy groups onto an elastomerbackbone. The elastomers may include styrene butadiene random and blockcopolymers, hydrogenated styrene butadiene random and block copolymers,acrylonitrile butadiene styrene (“ABS”) copolymers,ethylene-propylene-diene-monomer (EPDM) copolymers, styrene-acryliccopolymers, acrylonitrile butadiene rubber (NBR) polymers,methylmethacrylate butadiene styrene (MBS) rubbers, andstyrene-acrynitrile rubbers. Carboxy groups may be grafted onto ahydrophobic particulate elastomer to form a suitable graft particulateelastomer using a variety of suitable carboxylating materials,including, but not limited to, maleic acid, maleic anhydride, anddiesters and monoesters of maleic acid, maleimide, fumaric acid and itsderivatives, acrylic acid, alkylacrylate, alkylalkacrylates, acrylamide,2-acrylamido-2-methyl-1-propanesulfonic acid and its salts.

Examples of suitable graft particulate elastomers include, but are notlimited to, maleated polybutadienes, maleated styrene butadiene rubbers(“SBR”), maleated acrylonitrile-styrene-butadiene (“ABS”) rubbers,maleated nitrile-butadiene rubbers (“NBR”), maleated hydrogenatedacrylonitrile butadiene rubbers (“HNBR”), methylmethacrylate butadienestyrene (“MBS”) rubbers, carboxylated ethylene-propylene-diene monomerrubbers, carboxylated styrene-acrylonitrile rubbers (“SAN”),carboxylated ethylene propylene diene rubbers (“EPDM”), acrylic graftedsilicone rubbers, and combinations thereof. An example of a suitablehydrogenated acrylonitrile butadiene rubber (“HNBR”) that is graftedwith carboxylating materials is available from Lanxess Corporation,Leverkusen, Germany, under the trade name THERBAN® XT. An example of asuitable nitrile-butadiene rubbers (“NBR”) that is grafted withcarboxylating materials is available from Zeon Chemicals, L.P.,Louisville, Ky., under the trade name NIPOL® NBR 1072 CGX. Examples ofsuitable butadiene based rubbers that are grafted with carboxylatingmaterials are available from Mitsubishi Rayon Company Ltd., Tokyo,Japan, under the trade names METABLENS® C and E. An example of anacrylic rubber that is grafted with carboxylating materials is availablefrom Mitsubishi Rayon Company Limited, Tokyo, Japan, under the tradename METABLEN® W. An example of a suitable silicone based elastomer thatis grafted with carboxylating materials is available from MitsubishiRayon America Inc., New York, N.Y., under the trade name METABLEN® S. Anexample of a suitable styrene butadiene particulate elastomer graftedwith maleic acid available as an experimental product (Eliokem XPR-100)from Eliokem Corporation.

Most preferred are the grafted polyisoprene compounds including KuraryLIR403 which is a polyisoprene-graft-maleic anhydride having thefollowing chemical structure:

Also included is Kurary LIR410 which is a polyisoprene-graft-maleicanhydride monoester of maleic anhydride having the following chemicalstructure:

where n is approximately 10, and the material has a weight averagemolecular weight of about 25,000, and a glass transition temperature of−59° C.

The cover layer and/or one or more inner cover layers of the golf ballmay comprise one or more thermoplastic or thermoset polyurethanes orpolyureas. Polyurethanes or polyureas typically are prepared by reactinga diisocyanate with a polyol (in the case of polyurethanes) or with apolyamine (in the case of a polyurea). Thermoplastic polyurethanes orpolyureas may consist solely of this initial mixture or may be furthercombined with a chain extender to vary properties such as hardness ofthe thermoplastic. Thermoset polyurethanes or polyureas typically areformed by the reaction of a diisocyanate and a polyol or polyaminerespectively, and an additional crosslinking agent to crosslink or curethe material to result in a thermoset.

In what is known as a one-shot process, the three reactants,diisocyanate, polyol or polyamine, and optionally a chain extender or acuring agent, are combined in one step. Alternatively, a two-stepprocess may occur in which the first step involves reacting thediisocyanate and the polyol (in the case of polyurethane) or thepolyamine (in the case of a polyurea) to form a so-called prepolymer, towhich can then be added either the chain extender or the curing agent.This procedure is known as the prepolymer process.

In addition, although depicted as discrete component packages as above,it is also possible to control the degree of crosslinking, and hence thedegree of thermoplastic or thermoset properties in a final composition,by varying the stoichiometry not only of the diisocyanate-to-chainextender or curing agent ratio, but also the initialdiisocyanate-to-polyol or polyamine ratio. Of course in the prepolymerprocess, the initial diisocyanate-to-polyol or polyamine ratio is fixedon selection of the required prepolymer.

Finally, in addition to discrete thermoplastic or thermoset materials,it also is possible to modify a thermoplastic polyurethane or polyureacomposition by introducing materials in the composition that undergosubsequent curing after molding the thermoplastic to provide propertiessimilar to those of a thermoset. For example, Kim in U.S. Pat. No.6,924,337, the entire contents of which are hereby incorporated byreference, discloses a thermoplastic urethane or urea compositionoptionally comprising chain extenders and further comprising a peroxideor peroxide mixture, which can then undergo post curing to result in athermoset. Also, Kim et al. in U.S. Pat. No. 6,939,924, the entirecontents of which are hereby incorporated by reference, discloses athermoplastic urethane or urea composition, optionally also comprisingchain extenders, that is prepared from a diisocyanate and a modified orblocked diisocyanate which unblocks and induces further cross linkingpost extrusion. The modified isocyanate preferably is selected from thegroup consisting of: isophorone diisocyanate (IPDI)-based uretdione-typecrosslinker; a combination of a uretdione adduct of IPDI and a partiallye-caprolactam-modified IPDI; a combination of isocyanate adductsmodified by e-caprolactam and a carboxylic acid functional group; acaprolactam-modified Desmodur diisocyanate; a Desmodur diisocyanatehaving a 3,5-dimethyl pyrazole modified isocyanate; or mixtures ofthese.

Finally, Kim et al. in U.S. Pat. No. 7,037,985 B2, the entire contentsof which are hereby incorporated by reference, discloses thermoplasticurethane or urea compositions further comprising a reaction product of anitroso compound and a diisocyanate or a polyisocyanate. The nitrosoreaction product has a characteristic temperature at which it decomposesto regenerate the nitroso compound and diisocyanate or polyisocyanate.Thus, by judicious choice of the post-processing temperature, furthercrosslinking can be induced in the originally thermoplastic compositionto provide thermoset-like properties.

In view of the advantages of injection molding versus the more complexcasting process, under some circumstances it is advantageous to haveformulations capable of curing as a thermoset but only within aspecified temperature range above that of the typical injection moldingprocess. This allows parts, such as golf ball cover layers, to beinitially injection molded, followed by subsequent processing at highertemperatures and pressures to induce further crosslinking and curing,resulting in thermoset properties in the final part. Such an initiallyinjection moldable composition is thus called a post curable urethane orurea composition.

If a post curable urethane composition is required, a modified orblocked diisocyanate which subsequently unblocks and induces furthercross linking post extrusion may be included in the diisocyanatestarting material. Modified isocyanates used for making thepolyurethanes of the present invention generally are defined as chemicalcompounds containing isocyanate groups that are not reactive at roomtemperature, but that become reactive once they reach a characteristictemperature. The resulting isocyanates can act as crosslinking agents orchain extenders to form crosslinked polyurethanes. The degree ofcrosslinking is governed by type and concentration of modifiedisocyanate presented in the composition. The modified isocyanate used inthe composition preferably is selected, in part, to have acharacteristic temperature sufficiently high such that the urethane inthe composition will retain its thermoplastic behavior during initialprocessing (such as injection molding). If a characteristic temperatureis too low, the composition crosslinks before processing is completed,leading to process difficulties. The modified isocyanate preferably isselected from isophorone diisocyanate (IPDI)-based uretdione-typecrosslinker, a combination of a uretdione adduct of IPDI and a partiallye-caprolactam-modified IPDI; a combination of isocyanate adductsmodified by e-caprolactam and a carboxylic acid functional group; acaprolactam-modified Desmodur diisocyanate; a Desmodur diisocyanatehaving a 3,5-dimethyl pyrazole modified isocyanate; or mixtures ofthese. Particular preferred examples of modified isocyanates includethose marketed under the trade name CRELAN by Bayer Corporation.Examples of these include: CRELAN TP LS 2147; CRELAN NI 2; isophoronediisocyanate (IPDI)-based uretdione-type crosslinker, such as CRELAN VPLS 2347; a combination of a uretdione adduct of IPDI and a partiallye-caprolactam-modified IPDI, such as CRELAN VP LS 2386; a combination ofisocyanate adducts modified by e-caprolactam and a carboxylic acidfunctional group, such as CRELAN VP LS 2181/1; a caprolactam-modifiedDesmodur diisocyanate, such as CRELAN NW5; and a Desmodur diisocyanatehaving a 3,5-dimethyl pyrazole modified isocyanate, such as CRELAN XP7180. These modified isocyanates may be used either alone or incombination. Such modified diisocyanates are described in more detail inU.S. Pat. No. 6,939,924, the entire contents of which are herebyincorporated by reference.

As an alternative if a post curable polyurethane or polyurea compositionis required, the diisocyanate may further comprise reaction product of anitroso compound and a diisocyanate or a polyisocyanate. The reactionproduct has a characteristic temperature at which it decomposesregenerating the nitroso compound and diisocyanate or polyisocyanate,which can, by judicious choice of the post processing temperature, inturn induce further crosslinking in the originally thermoplasticcomposition resulting in thermoset-like properties. Such nitrosocompounds are described in more detail in U.S. Pat. No. 7,037,985 B2,the entire contents of which are hereby incorporated by reference.

The cover layer and/or one or more inner cover layers of the golf ballmay comprise one or more ionomer resins. One family of such resins wasdeveloped in the mid-1960's, by E.I.

DuPont de Nemours and Co., and sold under the trademark SURLYN®.Preparation of such ionomers is well known, for example see U.S. Pat.No. 3,264,272. Generally speaking, most commercial ionomers are unimodaland consist of a polymer of a mono-olefin, e.g., an alkene, with anunsaturated mono- or dicarboxylic acids having 3 to 12 carbon atoms. Anadditional monomer in the form of a mono- or dicarboxylic acid ester mayalso be incorporated in the formulation as a so-called “softeningcomonomer”. The incorporated carboxylic acid groups are then neutralizedby a basic metal ion salt, to form the ionomer. The metal cations of thebasic metal ion salt used for neutralization include Li⁺, Na⁺, K⁺, Zn²⁺,Ca²⁺, Co²⁺, Ni²⁺, Cu²⁺, Pb²⁺, and Mg²⁺, with the Li⁺, Na⁺, Ca²⁺, Zn²⁺,and Mg²⁺ being preferred. The basic metal ion salts include those of forexample formic acid, acetic acid, nitric acid, and carbonic acid,hydrogen carbonate salts, oxides, hydroxides, and alkoxides.

Today, there are a wide variety of commercially available ionomer resinsbased both on copolymers of ethylene and (meth)acrylic acid orterpolymers of ethylene and (meth)acrylic acid and (meth)acrylate, allof which can be used as a golf ball component. The properties of theseionomer resins can vary widely due to variations in acid content,softening comonomer content, the degree of neutralization, and the typeof metal ion used in the neutralization. The full range commerciallyavailable typically includes ionomers of polymers of general formula,E/X/Y polymer, wherein E is ethylene, X is a C₃ to C₈ α,β ethylenicallyunsaturated carboxylic acid, such as acrylic or methacrylic acid, and ispresent in an amount from about 0 wt. % to about 50 wt. %, particularlyabout 2 to about 30 weight %, of the E/X/Y copolymer, and Y is asoftening comonomer selected from the group consisting of alkyl acrylateand alkyl methacrylate, such as methyl acrylate or methyl methacrylate,and wherein the alkyl groups have from 1-8 carbon atoms, Y is in therange of 0 to about 50 weight %, particularly about 5 wt. % to about 35wt. %, of the E/X/Y copolymer, and wherein the acid groups present insaid ionomeric polymer are partially (e.g., about 1% to about 90%)neutralized with a metal selected from the group consisting of lithium,sodium, potassium, magnesium, calcium, barium, lead, tin, zinc oraluminum, or a combination of such cations.

The ionomer may also be a so-called bimodal ionomer as described in U.S.Pat. No. 6,562,906 (the entire contents of which are herein incorporatedby reference). These ionomers are bimodal as they are prepared fromblends comprising polymers of different molecular weights. Specificallythey include bimodal polymer blend compositions comprising:

-   -   a) a high molecular weight component having a molecular weight        of about 80,000 to about 500,000 and comprising one or more        ethylene/α, β-ethylenically unsaturated C₃₋₈ carboxylic acid        copolymers and/or one or more ethylene, alkyl (meth)acrylate,        (meth)acrylic acid terpolymers; said high molecular weight        component being partially neutralized with metal ions selected        from the group consisting of lithium, sodium, zinc, calcium,        magnesium, and a mixture of any these; and    -   b) a low molecular weight component having a molecular weight of        about from about 2,000 to about 30,000 and comprising one or        more ethylene/α, β-ethylenically unsaturated C₃₋₈ carboxylic        acid copolymers and/or one or more ethylene, alkyl        (meth)acrylate, (meth)acrylic acid terpolymers; said low        molecular weight component being partially neutralized with        metal ions selected from the group consisting of lithium,        sodium, zinc, calcium, magnesium, and a mixture of any these.

In addition to the unimodal and bimodal ionomers, also included are theso-called “modified ionomers” examples of which are described in U.S.Pat. Nos. 6,100,321, 6,329,458 and 6,616,552 and U.S. Patent PublicationNo. US 2003/0158312 A1, the entire contents of all of which are hereinincorporated by reference.

The modified unimodal ionomers may be prepared by mixing:

-   -   a) an ionomeric polymer comprising ethylene, from 5 to 25 weight        percent (meth)acrylic acid, and from 0 to 40 weight percent of a        (meth)acrylate monomer, said ionomeric polymer neutralized with        metal ions selected from the group consisting of lithium,        sodium, zinc, calcium, magnesium, and a mixture of any of these;        and    -   b) from about 5 to about 40 weight percent (based on the total        weight of said modified ionomeric polymer) of one or more fatty        acids or metal salts of said fatty acid, the metal selected from        the group consisting of calcium, sodium, zinc, potassium, and        lithium, barium and magnesium and the fatty acid preferably        being stearic acid.

The modified bimodal ionomers, which are ionomers derived from theearlier described bimodal ethylene/carboxylic acid polymers (asdescribed in U.S. Pat. No. 6,562,906, the entire contents of which areherein incorporated by reference), are prepared by mixing;

-   -   a) a high molecular weight component having a weight average        molecular weight (M_(w)) of about 80,000 to about 500,000 and        comprising one or more ethylene/α, β-ethylenically unsaturated        C₃₋₈ carboxylic acid copolymers and/or one or more ethylene,        alkyl (meth)acrylate, (meth)acrylic acid terpolymers; said high        molecular weight component being partially neutralized with        metal ions selected from the group consisting of lithium,        sodium, zinc, calcium, potassium, magnesium, and a mixture of        any of these; and    -   b) a low molecular weight component having a weight average        molecular weight (M_(w)) of about from about 2,000 to about        30,000 and comprising one or more ethylene/α, β-ethylenically        unsaturated C₃₋₈ carboxylic acid copolymers and/or one or more        ethylene, alkyl (meth)acrylate, (meth)acrylic acid terpolymers;        said low molecular weight component being partially neutralized        with metal ions selected from the group consisting of lithium,        sodium, zinc, calcium, potassium, magnesium, and a mixture of        any of these; and    -   c) from about 5 to about 40 weight percent (based on the total        weight of said modified ionomeric polymer) of one or more fatty        acids or metal salts of said fatty acid, the metal selected from        the group consisting of calcium, sodium, zinc, potassium and        lithium, barium and magnesium and the fatty acid preferably        being stearic acid.

The fatty or waxy acid salts utilized in the various modified ionomersare composed of a chain of alkyl groups containing from about 4 to 75carbon atoms (usually even numbered) and characterized by a —COOHterminal group. The generic formula for all fatty and waxy acids aboveacetic acid is CH₃ (CH₂)_(x)COOH, wherein the carbon atom count includesthe carboxyl group. The fatty or waxy acids utilized to produce thefatty or waxy acid salts modifiers may be saturated or unsaturated, andthey may be present in solid, semi-solid or liquid form.

Examples of suitable saturated fatty acids, i.e., fatty acids in whichthe carbon atoms of the alkyl chain are connected by single bonds,include but are not limited to stearic acid (C₁₈, i.e., CH₃(CH₂)₁₆COOH),palmitic acid (C₁₆, i.e., CH₃(CH₂)₁₄COOH), pelargonic acid (C₉, i.e.,CH₃(CH₂)₇COOH) and lauric acid (C₁₂, i.e., CH₃(CH₂)₁₀OCOOH). Examples ofsuitable unsaturated fatty acids, i.e., a fatty acid in which there areone or more double bonds between the carbon atoms in the alkyl chain,include but are not limited to oleic acid (C₁₃, i.e., CH₃(CH₂)₇CH:CH(CH₂)₇COOH).

The source of the metal ions used to produce the metal salts of thefatty or waxy acid salts used in the various modified ionomers aregenerally various metal salts which provide the metal ions capable ofneutralizing, to various extents, the carboxylic acid groups of thefatty acids. These include the sulfate, carbonate, acetate andhydroxylate salts of zinc, barium, calcium and magnesium.

Since the fatty acid salts modifiers comprise various combinations offatty acids neutralized with a large number of different metal ions,several different types of fatty acid salts may be utilized in theinvention, including metal stearates, laureates, oleates, andpalmitates, with calcium, zinc, sodium, lithium, potassium and magnesiumstearate being preferred, and calcium and sodium stearate being mostpreferred.

The fatty or waxy acid or metal salt of said fatty or waxy acid ispresent in the modified ionomeric polymers in an amount of from about 5to about 40, preferably from about 7 to about 35, more preferably fromabout 8 to about 20 weight percent (based on the total weight of saidmodified ionomeric polymer).

As a result of the addition of the one or more metal salts of a fatty orwaxy acid, from about 40 to 100, preferably from about 50 to 100, morepreferably from about 70 to 100 percent of the acidic groups in thefinal modified ionomeric polymer composition are neutralized by a metalion. An example of such a modified ionomer polymer is DuPont® HPF-1000available from E. I. DuPont de Nemours and Co. Inc.

The cover layer and/or one or more inner cover layers of the golf ballmay comprise a blend of an ionomer and a block copolymer. An example ofa block copolymer is a functionalized styrenic block copolymer, theblock copolymer incorporating a first polymer block having an aromaticvinyl compound, a second polymer block having a conjugated dienecompound in which the ratio of block copolymer to ionomer ranges from5:95 to 95:5 by weight, more preferably from about 10:90 to about 90:10by weight, more preferably from about 20:80 to about 80:20 by weight,more preferably from about 30:70 to about 70:30 by weight and mostpreferably from about 35:65 to about 65:35 by weight. A preferred blockcopolymer is SEPTON HG-252. Such blends are described in more detail incommonly-assigned U.S. Pat. No. 6,861,474 and U.S. Patent PublicationNo. 2003/0224871 both of which are incorporated herein by reference intheir entireties.

Another material which also may be used as a separate component of thecover layer or intermediate layer of the golf balls is a multi-componentblend composition (“MCBC”) prepared by blending together at least threematerials, identified as Components A, B, and C, and melt-processingthese components to form in-situ, a polymer blend compositionincorporating a pseudo-crosslinked polymer network. Such blends are morefully described in U.S. Pat. No. 6,930,150 to H. J. Kim, the entirecontents of which are hereby incorporated by reference.

The first of these blend components (blend Component A) include blockcopolymers including di and triblock copolymers, incorporating a firstpolymer block having an aromatic vinyl compound, and a second polymerblock having an olefinic and/or conjugated diene compound. Preferredaromatic vinyl compounds include styrene, α-methylstyrene, o-, m- orp-methylstyrene, 4-propylstyrene, 1,3-dimethylstyrene, vinylnaphthaleneand vinylanthracene. In particular, styrene and α-methylstyrene arepreferred. These aromatic vinyl compounds can each be used alone, or canbe used in combination of two or more kinds. The aromatic vinyl compoundis preferably contained in the block copolymer (b) in an amount of from5 to 75% by weight, and more preferably from 10 to 65% by weight.

The conjugated diene compound, that constitutes the polymer block B inthe block copolymer (b), includes, e.g., 1, 3-butadiene, isoprene, 2,3-dimethyl-1, 3-butadiene, 1, 3-pentadiene and 1, 3-hexadiene. Inparticular, isoprene and 1, 3-butadiene are preferred. These conjugateddiene compounds can each be used alone, or can be used in combination oftwo or more kinds.

Preferred block copolymers include the styrenic block copolymers such asstyrene-butadiene-styrene (SBS), styrene-ethylene-butylene-styrene,(SEBS) and styrene-ethylene-propylene-styrene (SEPS). Commercialexamples include SEPTON marketed by Kuraray Company of Kurashiki, Japan;TOPRENE by Kumho Petrochemical Co., Ltd and KRATON marketed by KratonPolymers.

Also included are functionalized styrenic block copolymers, includingthose where the block copolymer incorporates a first polymer blockhaving an aromatic vinyl compound, a second polymer block having aconjugated diene compound and a hydroxyl group located at a blockcopolymer, or its hydrogenation product. A preferred functionalizedstyrenic block copolymer is SEPTON HG-252.

The second blend component, Component B, is an acidic polymer thatincorporates at least one type of an acidic functional group. Examplesof such polymers suitable for use as include, but are not limited to,ethylene/(meth)acrylic acid copolymers and ethylene/(meth)acrylicacid/alkyl (meth)acrylate terpolymers, or ethylene and/or propylenemaleic anhydride copolymers and terpolymers. Examples of such polymerswhich are commercially available include, but are not limited to, theEscor® 5000, 5001, 5020, 5050, 5070, 5100, 5110 and 5200 series ofethylene-acrylic acid copolymers sold by Exxon Mobil, the PRIMACOR®1321, 1410, 1410-XT, 1420, 1430, 2912, 3150, 3330, 3340, 3440, 3460,4311, 4608 and 5980 series of ethylene-acrylic acid copolymers sold byThe Dow Chemical Company, Midland, Mich. and the ethylene-methacrylicacid copolymers such as Nucrel 599, 699, 0903, 0910, 925, 960, 2806, and2906 commercially available from DuPont

Also included are the so called bimodal ethylene/carboxylic acidpolymers as described in U.S. Pat. No. 6,562,906, the contents of whichare incorporated herein by reference. These polymers comprise a firstcomponent comprising an ethylene/a, β-ethylenically unsaturated C₃₋₈carboxylic acid high copolymer, particularly ethylene (meth)acrylic acidcopolymers and ethylene, alkyl (meth)acrylate, (meth)acrylic acidterpolymers, having a weight average molecular weight, Mw, of about80,000 to about 500,000, and a second component comprising anethylene/α, β-ethylenically unsaturated C₃₋₈ carboxylic acid copolymers,particularly ethylene/(meth)acrylic acid copolymers having weightaverage molecular weight, Mw, of about 2,000 to about 30,000.

Component C is a base capable of neutralizing the acidic functionalgroup of Component B and typically is a base having a metal cation.These metals are from groups IA, IB, IIA, IIB, IIIA, IIIB, IVA, IVB, VA,VB, VIA, VIB, VIIB and VIIIB of the periodic table. Examples of thesemetals include lithium, sodium, magnesium, aluminum, potassium, calcium,manganese, tungsten, titanium, iron, cobalt, nickel, hafnium, copper,zinc, barium, zirconium, and tin. Suitable metal compounds for use as asource of Component C are, for example, metal salts, preferably metalhydroxides, metal oxides, metal carbonates, metal acetates, metalstearates, metal laureates, metal oleates, metal palmitates and thelike.

The MCBC composition preferably is prepared by mixing the abovematerials into each other thoroughly, either by using a dispersivemixing mechanism, a distributive mixing mechanism, or a combination ofthese. These mixing methods are well known in the manufacture of polymerblends. As a result of this mixing, the acidic functional group ofComponent B is dispersed evenly throughout the mixture in either theirneutralized or non-neutralized state. Most preferably, Components A andB are melt-mixed together without Component C, with or without thepremixing discussed above, to produce a melt-mixture of the twocomponents. Then, Component C separately is mixed into the blend ofComponents A and B. This mixture is melt-mixed to produce the reactionproduct. This two-step mixing can be performed in a single process, suchas, for example, an extrusion process using a proper barrel length orscrew configuration, along with a multiple feeding system.

The TPUU-containing composition, UV-curable polyurethane composition andthe various other polymer compositions used to prepare core, mantle orouter cove layers of the golf balls may also incorporate one or morefillers. Such fillers are typically in a finely divided form, forexample, in a size generally less than about 20 mesh, preferably lessthan about 100 mesh U.S. standard size, except for fibers and flock,which are generally elongated. Flock and fiber sizes should be smallenough to facilitate processing. Filler particle size will depend upondesired effect, cost, ease of addition, and dusting considerations. Theappropriate amounts of filler required will vary depending on theapplication but typically can be readily determined without undueexperimentation.

The filler preferably is selected from the group consisting ofprecipitated hydrated silica, limestone, clay, talc, asbestos, barytes,glass fibers, aramid fibers, mica, calcium metasilicate, barium sulfate,zinc sulfide, lithopone, silicates, silicon carbide, diatomaceous earth,carbonates such as calcium or magnesium or barium carbonate, sulfatessuch as calcium or magnesium or barium sulfate, metals, includingtungsten steel copper, cobalt or iron, metal alloys, tungsten carbide,metal oxides, metal stearates, and other particulate carbonaceousmaterials, and any and all combinations thereof. Preferred examples offillers include metal oxides, such as zinc oxide and magnesium oxide. Inanother preferred embodiment the filler comprises a continuous ornon-continuous fiber.

In another preferred embodiment the filler comprises one or more socalled nanofillers, as described in U.S. Pat. No. 6,794,447 andcopending U.S. Publication No. US2004-0092336 filed on Sep. 24, 2003 andU.S. Pat. No. 7,332,533 filed on Aug. 25, 2004, the entire contents ofeach of which are incorporated herein by reference. Examples ofcommercial nanofillers are various Cloisite grades including 10A, 15A,20A, 25A, 30B, and NA+ of Southern Clay Products (Gonzales, Tex.) andthe Nanomer grades including 1.24TL and C.30EVA of Nanocor, Inc.(Arlington Heights, Ill.).

Materials incorporating nanofiller materials can provide these propertyimprovements at much lower densities than those incorporatingconventional fillers. For example, a nylon-6 nanocomposite materialmanufactured by RTP Corporation of Wichita, Kans. uses a 3% to 5% clayloading and has a tensile strength of 11,800 psi and a specific gravityof 1.14, while a conventional 30% mineral-filled material has a tensilestrength of 8,000 psi and a specific gravity of 1.36. Because use ofnanocomposite materials with lower loadings of inorganic materials thanconventional fillers provides the same properties, this use allowsproducts to be lighter than those with conventional fillers, whilemaintaining those same properties.

As used herein, a “nanocomposite” is defined as a polymer matrix havingnanofiller intercalated or exfoliated within the matrix. Physicalproperties of the polymer will change with the addition of nanofillerand the physical properties of the polymer are expected to improve evenmore as the nanofiller is dispersed into the polymer matrix to form ananocomposite.

Nanocomposite materials are materials incorporating from about 0.1% toabout 20%, preferably from about 0.1% to about 15%, and most preferablyfrom about 0.1% to about 10% of nanofiller reacted into andsubstantially dispersed through intercalation or exfoliation into thestructure of an organic material, such as a polymer, to providestrength, temperature resistance, and other property improvements to theresulting composite. Descriptions of particular nanocomposite materialsand their manufacture can be found in U.S. Pat. No. 5,962,553 toEllsworth, U.S. Pat. No. 5,385,776 to Maxfield et al., and 4,894,411 toOkada et al. Examples of nanocomposite materials currently marketedinclude M1030D, manufactured by Unitika Limited, of Osaka, Japan, and1015C2, manufactured by UBE America of New York, N.Y.

Preferably the nanofiller material is added to the polymeric compositionin an amount of from about 0.1% to about 20%, preferably from about 0.1%to about 15%, and most preferably from about 0.1% to about 10% by weightof nanofiller reacted into and substantially dispersed throughintercalation or exfoliation into the structure of the polymericcomposition.

If desired, the various polymer compositions used to prepare the golfballs can additionally contain other additives such as plasticizers,pigments, antioxidants, U.V. absorbers, optical brighteners, or anyother additives generally employed in plastics formulation or thepreparation of golf balls.

Another particularly well-suited additive for use in the presentlydisclosed compositions includes compounds having the general formula:

(R₂N)_(m)—R′—(X(O)_(n)OR_(y))_(m),

where R is hydrogen, or a C₁-C₂₀ aliphatic, cycloaliphatic or aromaticsystems; R′ is a bridging group comprising one or more C₁-C₂₀ straightchain or branched aliphatic or alicyclic groups, or substituted straightchain or branched aliphatic or alicyclic groups, or aromatic group, oran oligomer of up to 12 repeating units including, but not limited to,polypeptides derived from an amino acid sequence of up to 12 aminoacids; and X is C or S or P with the proviso that when X=C, n=1 and y=1and when X=S, n=2 and y=1, and when X=P, n=2 and y=2. Also, m=1-3. Thesematerials are more fully described in copending U.S. Provisional PatentApplication No. 60/588,603, filed on Jul. 16, 2004, the entire contentsof which are herein incorporated by reference. These materials includecaprolactam, oenantholactam, decanolactam, undecanolactam,dodecanolactam, caproic 6-amino acid, 11-aminoundecanoicacid,12-aminododecanoic acid, diamine hexamethylene salts of adipic acid,azeleic acid, sebacic acid and 1,12-dodecanoic acid and the diaminenonamethylene salt of adipic acid., 2-aminocinnamic acid, L-asparticacid, 5-aminosalicylic acid, aminobutyric acid; aminocaproic acid;aminocapyryic acid; 1-(aminocarbonyl)-1-cyclopropanecarboxylic acid;aminocephalosporanic acid; aminobenzoic acid; aminochlorobenzoic acid;2-(3-amino-4-chlorobenzoyl)benzoic acid; aminonaphtoic acid;aminonicotinic acid; aminonorbornanecarboxylic acid; aminoorotic acid;aminopenicillanic acid; aminopentenoic acid; (aminophenyl)butyric acid;aminophenyl propionic acid; aminophthalic acid; aminofolic acid;aminopyrazine carboxylic acid; aminopyrazole carboxylic acid;aminosalicylic acid; aminoterephthalic acid; aminovaleric acid; ammoniumhydrogencitrate; anthranillic acid; aminobenzophenone carboxylic acid;aminosuccinamic acid, epsilon-caprolactam; omega-caprolactam,(carbamoylphenoxy)acetic acid, sodium salt; carbobenzyloxy asparticacid; carbobenzyl glutamine; carbobenzyloxyglycine; 2-aminoethylhydrogensulfate; aminonaphthalenesulfonic acid; aminotoluene sulfonicacid; 4,4′-methylene-bis-(cyclohexylamine)carbamate and ammoniumcarbamate.

Most preferably the material is selected from the group consisting of4,4′-methylene-bis-(cyclohexylamine)carbamate (commercially availablefrom R.T. Vanderbilt Co., Norwalk, Conn. under the tradename Diak® 4),11-aminoundecanoicacid, 12-aminododecanoic acid, epsilon-caprolactam;omega-caprolactam, and any and all combinations thereof.

In an especially preferred embodiment a nanofiller additive component inthe golf ball is surface modified with a compatibilizing agentcomprising the earlier described compounds having the general formula:

(R₂N)_(m)—R′—(X(O)_(n)OR_(y))_(m),

A most preferred embodiment would be a filler comprising a nanofillerclay material surface modified with an amino acid including12-aminododecanoic acid. Such fillers are available from Nanonocor Co.under the tradename Nanomer 1.24TL.

Disclosed compositions have sufficient shear-cut resistance andexcellent mechanical properties that make them suitable for makingsports equipment, such as a recreation ball, a golf club or componentthereof, such as a grip, shoes, glove, helmet, protective gears,bicycle, football, soccer, basketball, baseball, volley ball, hockey,ski, skate and the like.

The cores of the golf balls may include the traditional rubbercomponents used in golf ball applications including, both natural andsynthetic rubbers, such as cis-1,4-polybutadiene,trans-1,4-polybutadiene, 1,2-polybutadiene, cis-polyisoprene,trans-polyisoprene, polychloroprene, polybutylene, styrene-butadienerubber, styrene-butadiene-styrene block copolymer and partially andfully hydrogenated equivalents, styrene-isoprene-styrene block copolymerand partially and fully hydrogenated equivalents, nitrile rubber,silicone rubber, and polyurethane, as well as mixtures of these.Polybutadiene rubbers, especially 1,4-polybutadiene rubbers containingat least 40 mol %, and more preferably 80 to 100 mol % of cis-1,4 bonds,are preferred because of their high rebound resilience, moldability, andhigh strength after vulcanization. The polybutadiene component may besynthesized by using rare earth-based catalysts, nickel-based catalysts,or cobalt-based catalysts, conventionally used in this field.Polybutadiene obtained by using lanthanum rare earth-based catalystsusually employ a combination of a lanthanum rare earth (atomic number of57 to 71)-compound, but particularly preferred is a neodymium compound.

The 1,4-polybutadiene rubbers have a molecular weight distribution(Mw/Mn) of from about 1.2 to about 4.0, preferably from about 1.7 toabout 3.7, even more preferably from about 2.0 to about 3.5, mostpreferably from about 2.2 to about 3.2. The polybutadiene rubbers have aMooney viscosity (ML₁₊₄ (100° C.)) of from about 20 to about 80,preferably from about 30 to about 70, even more preferably from about 30to about 60, most preferably from about 35 to about 50. The term “Mooneyviscosity” used herein refers in each case to an industrial index ofviscosity as measured with a Mooney viscometer, which is a type ofrotary plastometer (see JIS K6300). This value is represented by thesymbol ML₁₊₄ (100° C.), wherein “M” stands for Mooney viscosity, “L”stands for large rotor (L-type), “1+4” stands for a pre-heating time of1 minute and a rotor rotation time of 4 minutes, and “100° C.” indicatesthat measurement was carried out at a temperature of 100° C. As readilyappreciated by one skilled in the art, blends of polybutadiene rubbersmay also be utilized in the golf balls of the present invention, suchblends may be prepared with any mixture of rare earth-based catalysts,nickel-based catalysts, or cobalt-based catalysts derived materials, andfrom materials having different molecular weights, molecular weightdistributions and Mooney viscosity.

The cores of the golf balls may also include 1,2-polybutadienes havingdiffering tacticity, all of which are suitable as unsaturated polymersfor use in the presently disclosed compositions, are atactic1,2-polybutadiene, isotactic 1,2-polybutadiene, and syndiotactic1,2-polybutadiene. Syndiotactic 1,2-polybutadiene having crystallinitysuitable for use as an unsaturated polymer in the presently disclosedcompositions are polymerized from a 1,2-addition of butadiene. Thepresently disclosed golf balls may include syndiotactic1,2-polybutadiene having crystallinity and greater than about 70% of1,2-bonds, more preferably greater than about 80% of 1,2-bonds, and mostpreferably greater than about 90% of 1,2-bonds. Also, the1,2-polybutadiene may have a mean molecular weight between about 10,000and about 350,000, more preferably between about 50,000 and about300,000, more preferably between about 80,000 and about 200,000, andmost preferably between about 10,000 and about 150,000. Examples ofsuitable syndiotactic 1,2-polybutadienes having crystallinity suitablefor use in golf balls are sold under the trade names RB810, RB820, andRB830 by JSR Corporation of Tokyo, Japan.

The cores of the golf balls of the present invention may also includethe polyalkenamer rubbers as previously described herein and disclosedin U.S. Pat. No. 7,528,196 in the name of Hyun Kim et al., the entirecontents of which are hereby incorporated by reference.

Typically the golf ball core is made by mixing together the unsaturatedpolymer, cross-linking agents, and other additives with or withoutmelting them. Dry blending equipment, such as a tumbler mixer, Vblender, ribbon blender, or two-roll mill, can be used to mix thecompositions. The golf ball core compositions can also be mixed using amill, internal mixer such as a Banbury or Farrel continuous mixer,extruder or combinations of these, with or without application ofthermal energy to produce melting. The various core components can bemixed together with the cross-linking agents, or each additive can beadded in an appropriate sequence to the milled unsaturated polymer. Inanother method of manufacture the cross-linking agents and othercomponents can be added to the unsaturated polymer as part of aconcentrate using dry blending, roll milling, or melt mixing. Ifradiation is a cross-linking agent, then the mixture comprising theunsaturated polymer and other additives can be irradiated followingmixing, during forming into a part such as the core of a ball, or afterforming.

The resulting mixture can be subjected to, for example, a compression orinjection molding process, to obtain solid spheres for the core. Thepolymer mixture is subjected to a molding cycle in which heat andpressure are applied while the mixture is confined within a mold. Thecavity shape depends on the portion of the golf ball being formed. Thecompression and heat liberates free radicals by decomposing one or moreperoxides, which initiate cross-linking. The temperature and duration ofthe molding cycle are selected based upon the type of peroxide andpeptizer selected. The molding cycle may have a single step of moldingthe mixture at a single temperature for fixed time duration.

For example, a preferred mode of preparation for the cores used in thepresent invention is to first mix the core ingredients on a two-rollmill, to form slugs of approximately 30-40 g, and then compression-moldin a single step at a temperature between 150 to 180° C., for a timeduration between 5 and 12 minutes.

The various core components may also be combined to form a golf ball byan injection molding process, which is also well known to one ofordinary skill in the art. The curing time depends on the variousmaterials selected, and those of ordinary skill in the art will bereadily able to adjust the curing time upward or downward based on theparticular materials used and the discussion herein.

The various formulations for the intermediate layer and/or cover layermay be produced by any generally known method, such as dry blending,melt-mixing, or combination of those, to achieve a good dispersivemixing, distributive mixing, or both. Examples of melt-mixing areroll-mill; internal mixer, such as injection molding, single-screwextruder, twin-screw extruder; or any combination of those The feed tothe injection mold may be blended manually or mechanically prior to theaddition to the injection molder feed hopper. Finished golf balls may beprepared by initially positioning the solid, preformed core in aninjection-molding cavity, followed by uniform injection of theintermediate layer and/or cover layer composition sequentially over thecore. The cover formulations can be injection molded around the cores toproduce golf balls of the required diameter.

Alternatively, the intermediate layers and/or outer cover layer may alsobe formed around the core by first forming half shells by injectionmolding followed by compression molding the half shells about the coreto form the final ball.

The intermediate layers and/or outer cover layer may also be formedaround the cores using compression molding. Cover materials forcompression molding may also be extruded or blended resins or castableresins such as thermoset polyurethane or thermoset polyurea.

The golf ball of the present invention comprises a core and may comprisefrom 0 to 6, preferably from 0 to 5, more preferably from about 1 toabout 4, most preferably from about 1 to about 3 intermediate or mantlelayer(s).

In one preferred aspect, the golf ball is a three-piece ball with theTPUU- or the UTPU-containing blend composition used in the intermediatelayer.

In one preferred aspect, the golf ball is a three-piece ball with theTPUU- or the UTPU-containing blend composition used in the cover layer.

In one preferred aspect, the golf ball is a four-piece, five-piece, orsix-piece ball having at least one intermediate layer which comprisesthe TPUU- or the UTPU-containing blend material described herein.

In one preferred aspect, the golf ball is a four-piece, five-piece, orsix-piece ball wherein the cover layer comprises the TPUU- or theUTPU-containing blend material described herein.

In another aspect the golf ball is a three-piece ball with theintermediate layer comprising the TPUU- or the UTPU-containing blendmaterial and the outer cover layer comprises a block copolymer, anacidic polymer, a unimodal ionomer, a bimodal ionomer, a modifiedunimodal ionomer, a modified bimodal ionomer, a polyalkenamer, apolyamide, a thermoplastic or thermoset polyurethane or thermoplastic orthermoset polyurea, or a multicomponent blend composition (“MCBC”), theMCBC comprising (A) a block copolymer; and (B) one or more acidicpolymers; and (C) one or more basic metal salts present in an amount toneutralize at greater than or equal to about 30 percent of the acidgroups of Component (B), and any and all combinations thereof.

In another aspect the golf ball is a four-piece ball with a unitary coreand one or both of the intermediate layers comprises the TPUU or theUTPU-containing blend material and the outer cover layer comprises ablock copolymer, an acidic polymer, a unimodal ionomer, a bimodalionomer, a modified unimodal ionomer, a modified bimodal ionomer, apolyalkenamer, a polyamide, a thermoplastic or thermoset polyurethane orthermoplastic or thermoset polyurea, or a multicomponent blendcomposition (“MCBC”), the MCBC comprising (A) a block copolymer; and (B)one or more acidic polymers; and (C) one or more basic metal saltspresent in an amount to neutralize at greater than or equal to about 30percent of the acid groups of Component (B), and any and allcombinations thereof.

In another aspect the golf ball is a five-piece ball with a unitary coreand one or more of the three intermediate layers comprises the TPUU- orthe UTPU-containing blend material and the outer cover layer comprises ablock copolymer, an acidic polymer, a unimodal ionomer, a bimodalionomer, a modified unimodal ionomer, a modified bimodal ionomer, apolyalkenamer, a polyamide, a thermoplastic or thermoset polyurethane orthermoplastic or thermoset polyurea, or a multicomponent blendcomposition (“MCBC”), the MCBC comprising (A) a block copolymer; and (B)one or more acidic polymers; and (C) one or more basic metal saltspresent in an amount to neutralize at greater than or equal to about 30percent of the acid groups of Component (B), and any and allcombinations thereof.

In another aspect the golf ball is a six-piece ball with a unitary coreand the one or more of the four intermediate layers comprises the TPUU-or the UTPU-containing blend material and the outer cover layercomprises a block copolymer, an acidic polymer, a unimodal ionomer, abimodal ionomer, a modified unimodal ionomer, a modified bimodalionomer, a polyalkenamer, a polyamide, a thermoplastic or thermosetpolyurethane or thermoplastic or thermoset polyurea, or a multicomponentblend composition (“MCBC”), the MCBC comprising (A) a block copolymer;and (B) one or more acidic polymers; and (C) one or more basic metalsalts present in an amount to neutralize at greater than or equal toabout 30 percent of the acid groups of Component (B), and any and allcombinations thereof.

The one or more intermediate layers of the golf balls may have athickness of from about 0.010 to about 0.400, preferably from about0.020 to about 0.200 and most preferably from about 0.030 to about 0.100inches.

The one or more intermediate layers of the golf balls may also have aShore D hardness as measured on the ball of greater than about 25,preferably greater than about 40, and most preferably greater than about50 Shore D units.

The outer cover layer of the balls may have a thickness of from about0.015 to about 0.100, preferably from about 0.020 to about 0.080, morepreferably from about 0.025 to about 0.060 inches.

The outer cover layer the balls may also have a Shore D hardness asmeasured on the ball of from about 30 to about 75, preferably from 38 toabout 68 and most preferably from about 40 to about 65.

The core of the balls also may have a PGA compression of less than about140, preferably less than about 100, and most preferably less than about90.

The various core layers (including the center) if present may eachexhibit a different hardness. The difference between the center hardnessand that of the next adjacent layer, as well as the difference inhardness between the various core layers may be greater than 2,preferably greater than 5, most preferably greater than 10 units ofShore D.

In one preferred aspect, the hardness of the center and each sequentiallayer increases progressively outwards from the center to outer corelayer.

In another preferred aspect, the hardness of the center and eachsequential layer decreases progressively inwards from the outer corelayer to the center.

The core of the balls may have a diameter of from about 0.5 to about1.62, preferably from about 0.7 to about 1.60, more preferably fromabout 0.9 to about 1.58, yet more preferably from about 1.20 to about1.54, and even more preferably from about 1.40 to about 1.50 in.

More specifically, for a three piece golf ball consisting of a core, amantle, and a cover, the diameter of the core is most preferably greaterthan or equal to 1.41 inches in diameter.

More specifically, for a four piece golf ball (consisting of a core, aninner mantle, an outer mantle, and a cover wherein the inner mantle isencased by an outer mantle) the diameter of the core is most preferablygreater than or equal to 1.00 inches in diameter.

More specifically, for a five piece golf ball (consisting of an innercore, an outer core, an inner mantle, an outer mantle, and a coverwherein the inner core and inner mantle are encased by outer core andouter mantle, respectively) the diameter of the core is most preferablygreater than or equal to 1.00 inches in diameter.

More specifically, for a six piece golf ball (consisting of an innercore, an intermediate core, an outer core, an inner mantle, an outermantle, and a cover wherein the intermediate core and inner mantle areencased by outer core and outer mantle, respectively) the diameter ofthe core is most preferably greater than or equal to 1.00 inches indiameter.

More specifically, for a six piece golf ball (consisting of an innercore, an outer core, an inner mantle, an intermediate mantle, an outermantle, and a cover wherein the intermediate core and inner mantle areencased by outer core and outer mantle, respectively) the diameter ofthe core is most preferably greater than or equal to 1.00 inches indiameter.

The COR of the golf balls may be greater than about 0.700, preferablygreater than about 0.730, more preferably greater than 0.750, mostpreferably greater than 0.775, and especially greater than 0.800 at 125ft/sec inbound velocity.

The shear cut resistance of the golf balls of the present invention isless than about 4, preferably less than about 3, even more preferablyless than about 2.

In view of the many possible embodiments to which the principles of thedisclosed invention may be applied, it should be recognized that theillustrated embodiments are only preferred examples of the invention andshould not be taken as limiting the scope of the invention.

What is claimed is:
 1. A golf ball comprising: (A) a core; (B)optionally, at least one intermediate layer; and (C) a cover layer,wherein the cover layer or the intermediate layer comprises apolyurethane-urea composition that is the reaction product of: (i) athermoplastic polyurethane-urea formed as a reaction product of (a) adiol or polyol, (b) a first isocyanate, and (c) an amine chain extender;and (ii) a crosslinking agent.
 2. A golf ball comprising: (A) a core;(B) optionally, at least one intermediate layer; and (C) a cover layer,wherein the cover layer or the intermediate layer comprises apolyurethane-urea composition that is formed from: (i) a crosslinkedpolyurethane-urea that is a reaction product of (a) a diol or polyol,(b) a first isocyanate, and (c) an amine chain extender.
 3. The golfball of claim 1, wherein the crosslinking agent is selected from adiamine, a second amine, a blocked amine, a second isocyanate, a blockedisocyanate, a polyamine, a polyisocyanate, a peroxide, asulfur-containing compound, or any combination thereof.
 4. The golf ballof claim 1, wherein the crosslinking agent is a second isocyanate. 5.The golf ball of any one of claim 1, wherein the cover layer comprisesthe polyurethane-urea composition.
 6. A golf ball comprising: (A) acore; (B) optionally, at least one intermediate layer; and (C) a coverlayer, wherein the cover layer or the intermediate layer comprises aUV-cured polyurethane.
 7. A golf ball comprising: (A) a core; (B)optionally, at least one intermediate layer; and (C) a cover layer,wherein the cover layer or the intermediate layer comprises acrosslinked polyurethane composition that is formed from a UV-curablethermoplastic polyurethane.
 8. The golf ball of claim 7, wherein theUV-curable thermoplastic polyurethane includes UV-curable (meth)acrylicfunctional groups.
 9. A method for making a golf ball comprising:forming a layer over a golf ball core or forming a layer over a golfball intermediate layer, wherein the layer comprises a crosslinkablethermoplastic polyurethane-urea that is a reaction product of (a) a diolor polyol, (b) a first isocyanate, and (c) an amine chain extender; andcrosslinking the crosslinkable thermoplastic polyurethane-urea.
 10. Amethod for making a golf ball comprising: forming a layer over a golfball core or forming a layer over a golf ball intermediate layer,wherein the layer comprises a UV-crosslinkable thermoplasticpolyurethane; and irradiating the layer with UV light under conditionssufficient for crosslinking the UV-crosslinkable thermoplasticpolyurethane.